Development
kit for the RPC transceiver
Issue C, 17th April 1998 RPC Dev Kit
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RPC-DEV is a designers development kit for the RPC transceiver.
It contains 2 complete sets of hardware for a point to point link,
each end may be operated in one of 3 operating modes:
1. Stand alone
Selects the RPC's internal diagnostic modes 0 to 8
Enables self-test, range testing and software debugging.
2. PC driven link
RPC is controlled directly by a Standard Printer Port
(SPP with Open Collector / Pull-up control lines) or Extended Capabilities
Port (ECP) set to Byte Mode or PS/2 Mode. PC software
supplied with the kit enables display and editing all RPC internal
registers.
Data packets may be sent to and received from other RPCs. Software
is supplied on 3.5" disk and runs under MS-DOS.
3. PIC development
The RPC-DEV PCB will accept a wide range of 18 &
28 pin Arizona Microsystems PIC micro controllers for product development.
RPC driver subroutine source code is included.
Kit contents
-
| Qty |
Item |
Description |
| 2 |
RPC (418 or 433.92Mhz) |
Packet transceivers
+ Antennas. |
| 2 |
Development PCB's |
Fully populated.
|
| 2 |
PC cables |
Standard 18/25 way
'D' printer cables (M>F) |
| 2 |
RPCPS2CAB cables |
SPP to PS2 Interface
Cables |
| 1 |
3.5" Floppy
Disk |
MS-DOS PC Driver
software for the RPC.
RPC utility software including sample drivers. |
| 1 |
set of data sheets |
BiM & RPC data
sheets
Circuit / layout diagrams and documentation
for the Development PCB's. |
Required but not supplied:
1. A power supply of 7V to 12V DC @ <60mA (typ 20 to 40mA). (PSU
or PP3)
2. MS-DOS PC or laptop with LPT1 set to Standard Printer Port (SPP
with Open
collector / pull-up) or Extended Capabilities Port (ECP) set to Byte
Mode or PS/2
Mode.
3. PIC microcontrollers / PIC development tools.(only required for
mode 3)
1. Standalone Operation
This mode selects the internal diagnostics built into
the RPC.
Set-up
- Connect the antenna into the Antenna (R.H.) terminal
on the RPC and plug the RPC into the development PCB.
- Connect a DC supply/9V battery to the supply input
terminals and switch on.
- Select 'Debug' on the debug/normal switch and press
'RPC Reset'
- The Hex switch selects the required debug mode
0 to 8. An RPC reset is not required after a mode change. Debug
must not be used when a PIC is inserted or a PC is connected to
the Development PCB.
Test modes:
SELF TEST (debug mode 8)
8 on the hex switch selects the RPC's internal self
test. The RPC puts the BiM transceiver into local loop back (both
TX & RX on), a test code is continuously sent and recovered. The
RXR LED on the development PCB will light to indicate a pass.
RADAR (debug mode 7)
7 on the hex switch will cause the RPC to repetitively
send an ASCII test packet - "Radiometrix RPC v 1.0 XX",
where XX is an incrementing packet counter 00 to 63. A remote unit
in Radar mode is very useful for checking and debugging user RPC upload
(RX) host software.
Additionally, Radar mode listens for a short time
between each packet for an echo (see mode 6) and will light the RXR
LED if a valid packet is received. This 'ping-pong' function is very
effective for range / antenna tests.
ECHO (debug mode 6)
6 on the hex switch will cause the RPC to ECHO (retransmit)
any valid packets it receives (transponder). Echo is very useful for
remote loop-back testing of user host software and for "ping-pong"
range testing in conjunction with the other development PCB in RADAR
mode.The RXR LED flashes each time a packet is echoed.
Debug modes 0 - 5
These modes are primarily designed for radio performance
testing with RF test gear and are described in the RPC data sheet.
RPC Dev Kit contains 2 pairs of cables
Standard Parallel Cable with Moulded Connectors on both ends for
SPP with Open Collector / pull-up control lines.
RPCPS2CAB (SPP to PS/2 Interface Cable) with Black Assembled Cover
on Male connector for PS/2 port or ECP port set to Byte Mode or
PS/2 compatible mode.
2. PC or Laptop Operation
Set-up
- Connect the antenna into the Antenna (R.H.) terminal
on the RPC and plug the RPC into the development PCB.
- Connect a DC supply/9V battery to the supply input
terminals and switch on.
- Connect the development PCB to the LPT1 port of
a PC or Laptop with the 25 way lead supplied. (standard 18 or 25
way 1:1 'D' cable or RPSPS2CAB cable has to be used for new PC's
with ECP port).
- Select 'Normal' on the debug/normal switch. Select
'F' (open circuit) on the hex switch.
Note: During PC operation, the
hex debug switch must be on 'F' and no PIC microcontroller inserted
(or it must be tri-stated).
- Copy all the supplied files into a suitable directory
on your hard disk.
Software Overview:
The software supplied has been written to allow an
RPC developer to gain immediate access to a Radiometrix RPC module
and enables message send/receive and RPC memory examine/modify .
The 3.5" disk contains two versions of the software:
1. For Standard Parallel Port (SPP
with Open Collector / pull-up control lines) in old PCs.
| RPC.DOC |
RPC Dec Kit documentation. |
| RPC.EXE |
main RPC driver program |
| RPC.DAT |
ASCII data file holds
system information used by RPC.EXE |
| DATA-A.TXT |
sample ASCII test files |
| DATA-B.TXT |
|
| DATA-C.TXT |
|
| DATA-D.TXT |
|
| DATA-E.TXT |
|
2. For Bidirectional PS/2 or Extended
Capabilities Port (ECP) in new PCs
Bidirectional version of the software is in the subdirectory
\RPC_BI
It contains the following files:
| DEMO.BAT |
Batch file to set the
Byte Mode or PS/2 Mode in ECP before running RPC software. |
| README.DOC |
RPC Dev Kit documentation |
| RPC-BI.EXE |
main PS/2 RPC driver
program |
| RPC.DAT |
ASCII data file holds
system information used by RPC-BI.EXE |
| D.A |
sample ASCII test files |
| D.B |
|
| D.C |
|
| D.D |
|
| D.E |
|
| Note: |
SPP version of the RPC Dev Kit software
(RPC.EXE) will not work properly with new PCs. Bidirectional
PS/2 versions of the RPC Dev Kit software need to be used in
this case. Extended Capabilities Port (ECP) can be set to Byte
Mode or PS/2 compatible mode. ECP_PS2.EXE program will change
the mode to PS/2 compatible mode. PS2_ECP.EXE will change it
back to ECP mode. |
The main program RPC.EXE is designed to run under
MS-DOS 3.3 or higher on any IBM PC or compatible with a Standard Printer
Port (SPP with Open Collector / pull-up control lines) or Extended
Capabilities Port (ECP) set to Byte Mode or PS/2 Mode,
set-up as LPT1.
Using this program, it is possible gain access to
the onboard EEPROM to evaluate the extended functionality provided
via the Reserved Memory settings and to also read/write the User EEPROM
area.
The program provides a set of commands allowing the
user to operate the RPC module. These command functions enable the
user to include send and receive messages, write to EEPROM memory,
send continuous messages to the RPC and enable the 7 RPC reset modes.
Upon start-up of the utility if an RPC is connected
to the parallel port and is working, the Reserved Memory and User
Memory areas of the display will be updated.
The Outgoing and Incoming message area can be expanded
or reduced as the user requires by pressing the TAB key (or alternatively
entering switcH at the command prompt). This has the effect of either
hiding or showing the user memory area. In order to view the help
list properly the display needs to be in the expanded mode.
Messages sent from the RPC are displayed under the
Outgoing (TX) message heading to the left of the display. Messages
received by the RPC are displayed under the Incoming (RX) heading
to the right of the display.
Command set:
The following list has been taken from the RPC demonstration
program and details the commands which are available
for evaluating the RPC.
| COMMAND
|
DESCRIPTION
|
|
|
| Reset [n]
|
Reset the RPC; Test
mode (n = 0 - 8) |
| reaD address
|
Read from memory address
(Addr = 00 - 3F) |
| Send [$] string
|
Transmit string via
RPC; $ selects preamble |
| Write address
data |
Write data to RPC memory
address (00 - 3F) |
| Clear
|
Clear the display output
window |
| switcH or <TAB> |
toggle memory display
window On/Off |
| File [delay]
file [file...] |
Send a file(s) to the
RPC |
|
delay = delay between
files (0.25s increments) |
| Test
|
execute the file send
test list |
| stoP or <^X>
|
to stop repeating file
send (Test & File) |
| Help
|
Display this help information |
| eXit or <F3>
|
Exit from this demo
program |
| <ESC>
|
Erase current command
line |
| <TAB>
|
Switch display between
memory and output |
note:
- The capital letter in each command may be used in place of the
full word.
- All values required by specific commands should be entered in
hex.
Commands in Detail:
Note:
Square brackets [] means the argument(s) are optional.
Angle brackets <> means the argument(s) are required.
The capital letter in the command represents an abbreviation of that
command.
| Reset [0-8] |
send a RESET to the
RPC. |
|
sets the RPC into the
specified demo mode. |
|
example: >R
reset RPC |
|
>R7
reset RPC into debug mode 7 (RADAR) |
|
|
| reaD <address> |
read the EEPROM memory
at location <address> |
|
the address should be
in the range of 0x00 - 0x3F |
|
e.g.: >read
20 |
|
|
| Send [$] <string> |
Transmit the given string
via the RPC |
|
Preceding the string
with a $ sign will enable extended preamble to be used when transmitting
the packet. If more than 27 bytes of data are entered on the command
line, the string will be broken into 2 RPC packets and transmitted. |
|
example: >S
THIS IS A TEST send 'THIS IS A TEST' |
|
>S$Is
any body out there ? ; extended preamble |
|
|
| Write <addr>
<data> |
Write data to the specified
RPC EEPROM location. |
|
The allowable memory
range is from 0x00 to 0x3F. Data represents a single byte between
0x00 - 0xFF. |
|
example: >W
00 4 writes 04h into SWITCHES (00h) |
|
>W
08 80 will set PS1 on reset |
|
|
| eXit or <F3> |
Typing either EXIT or
X, or pressing F3 will exit from the demonstration program back
to the command prompt. |
|
|
| Clear |
Clear the display output
window. |
|
|
| stoP or <^X> |
Stop the repeating file
send (Test & File commands). |
|
|
| Help |
Display this help information
as shown in section RPCDEMO commands. |
|
|
| <TAB> |
Switches the display
between the memory display and the expanded output display. |
|
|
| <ESC> |
Clear the current command
line |
|
|
| File [delay]
file [file...] |
Send a file to the RPC.
A maximum of 3 files can be givenon the command line. The file
names should contain only alpha characters (e.g. fred1.txt <-
not allowed. freda.txt <- allowed). The [dly] enables a delay
of between 0x00 and 0xFF seconds between files being sent. Using
the delay will enable the files to be repeated continuously using
the delay value between them. Without the delay value the file(s)
will only be sent once. |
|
This is NOT a file transfer
function. i.e.; it will not copy the file to the destination. |
|
If any lines in the
file contain more than 27 bytes, the line will be broken into
multiple blocks of 27 bytes. They will NOT be reassembled into
full lines by the receiver. |
|
e.g. file 2 autoexec.bat
config.sys |
|
example: >F
RPC.DOC transmits this file |
|
|
| Test |
Execute the test file
command line from the RPC.DAT file |
|
See RPC Configuration
File details later for a description of RPC.DAT command line used
with this command. |
|
example: >T
repetitively sends the test files. |
RPC Configuration File:
The demonstration program requires a configuration
file. This file is called RPC.DAT. Following is an example RPC.DAT
file:
PORT = 378
COLOUR = 0
FILE = 2 rpc.dat c:\config.sys
PORT = <xxx>
This entry determines the base address of the PC printer port.
The value is entered as a hex value.
COLOUR = <0 | 1>
This is a Boolean of either 0 or 1.
Setting this entry to 0 disables the colour display. i.e.; all output
will be in black and white. This is suitable for a monochrome display
device such as a laptop.
Setting this entry to 1 will enable the coloured output.
FILE = <delay> <file1> <file2> <file3>
This entry has the same format as the FILE command.
It is the command line used when the TEST command is entered.
Interrupt selection:
The RPC driver program uses interrupts therefor the
two IRQ jumpers on the RPC Development PCB should be fitted. If a
PC based RPC driver is being developed it is often desirable to use
interrupt driven software. If the IRQ jumpers are fitted a +ve going
interrupt (std) will be generated when either/or RXR or TXA from the
RPC become active.
3. PIC Microcontroller Development
The PIC range of microcontrollers from Arizona Microsystems
are well suited to act as host controllers for the RPC. The RPC Development
kit will accommodate the following PIC's:
| low cost |
18pin |
PIC16C54, PIC16C56
& PIC16C58 |
| mid performance |
18pin |
PIC16C61, PIC16C62x,
PIC16C71 & PIC16C84 |
| larger I/O |
28pin |
PIC16C62, PIC16C63,
PIC16C73A & PIC16C76 |
In all cases port B (RB0 - RB7) is dedicated to driving
the RPC, sample driver subroutines are included on disk.
Port A and Port C (28pin PIC's) are brought out to
a standard pin headers together with supply and reset lines to allow
connection of user developed hardware. A 10.240 MHz XTAL is fitted
as standard but may be changed to suit user requirements.
Setup
- Connect the antenna into the Antenna (R.H.) terminal
on the RPC and plug the RPC into the development PCB.
- Connect a DC supply/9V battery to the supply input
terminals.
- Select 'Normal' on the debug/normal switch, select
'F' on the hex switch.
- Insert a PIC or ICE into either the 18 or 28 pin
PIC socket + any custom hardware.
note:
The 'F' on the hex switch is all off (open circuit) During PIC operation,
the hex debug switch must be on 'F' and the PC must not be connected.
Appendix A
For Old PCs: Standard Parallel Port (SPP with open collector
/ pull-up control lines)
This is the default RPC Dev Kit configuration. It will work properly
only on old PCs which have Standard Parallel Port (SPP) with open
collector / pull-up control lines. RPC.EXE has to be used with this
configuration.
Bidirectional PS/2 port configuration has to be used for new PCs
which have PS/2 compatible ports or Extended Capabilities Port (ECP).
DEMO.BAT (RPC-BI.EXE)
in \RPC-BI subdirectory has to used with PS/2 mode configuration.
25 way Male D Connector on the RPC Dev Kit is connected to the RPC
with the connections shown on the table below. The cable which comes
with the Kit is one to one Female to Male 25 way cable. It can only
be used with the default configuration.
To use the Bidirectional PS/2 mode, interface adapter or cable has
to be used to change the connections as shown in Figure
1.
Connections: RPC to 25 WAY 'D' printer port
| Port requirement |
Standard Printer Port (SPP) |
|
with Open Collector / Pull-up Control lines |
|
|
| name
|
pin
|
|
pin
|
Bit Name |
Pin Labels |
| |
|
|
|
|
|
| GND
|
1
|
|
18 to 25
|
|
Ground |
| D0
|
2
|
 |
1
|
C0
|
-Strobe |
| D1
|
3
|
|
14
|
C1
|
-Auto Linefeed |
| D2
|
4
|
|
16
|
C2
|
-Initialise Printer |
| D3
|
5
|
|
17
|
C3
|
-Select Printer |
| TXR
|
6
|
 |
2
|
D0
|
Data 0 |
| TXA
|
7
|
 |
12
|
S5
|
+Paper Out |
| RXR
|
8
|
|
13
|
S4
|
+Printer Selected |
| RXA
|
9
|
|
3
|
D1
|
Data 1 |
| RES
|
10
|
|
4
|
D2
|
Data 2 |
| 5 volt
|
11
|
|
+5V supply
|
|
|
| GND
|
12
|
|
0V supply
|
|
|
| +ve interrupt
|
|
|
10
|
S6
|
-Acknowledge |
PC printer port registers (addresses
given for base address of 0378)
| 0378
|
data register
|
b7
|
b6
|
b5
|
b4
|
b3
|
b2
|
b1
|
b0
|
| |
|
-
|
-
|
-
|
-
|
-
|
RES
|
RXR
|
TXA
|
| |
| 0379
|
status register
|
b7
|
b6
|
b5
|
b4
|
b3
|
b2
|
b1
|
b0
|
| |
|
- |
Int |
TXA |
RXR |
- |
- |
- |
- |
| |
| 037A
|
control register
|
b7
|
b6
|
b5
|
b4
|
b3
|
b2
|
b1
|
b0
|
| |
|
-
|
-
|
dir
|
Ien
|
D3
|
D2
|
D1
|
D0
|
|
|
| int |
+ve transition interrupt bit, see "interrupt
drive" |
| Ien |
bit is internal interrupt enable, not used if
polling used |
|
1 = interrupt enable , 0 = disabled (polled operation) |
note: D0, D1 and D3 pins are
inverted drives from the register i.e. a 1 in the control
register gives a 0 on the pin all other registers
/ bits are true.
Cautions:
| 1. |
Many laptops use 3.3
Volt logic on the printer port pins. This will work directly with
a 5 Volt RPC with the exception of the RPC's reset line which
must be level shifted to 5 Volt logic.(the RPC Dev Kit does this) |
|
|
| 2. |
If you are writing PC
Drivers beware of the long noise suppression time constants (upto
10µs) often used on some/all of the pins of the printer port.
Beware of AND/OR instructions which act directly on the port registers
as the data may not have settled from previous writes' to the
port, it's safer to keep and use an indirect copy of the port
registers in memory. |
For
New PCs: Bidirectional Port (PS/2)
| Port requirement |
8 bit Bidirectional Port |
|
PS/2 or ECP set to PS/2 Mode /
Byte Mode |
| cable |
RPCPS2CABLE |
This configuration is needed for new PCs because the Standard Parallel
Port (SPP) in new PCs does not contain open collector / pull-up control
lines as in older PCs. SPP version of the software uses Printer Port
Control lines as RPC Data lines. Data lines are pulled low by RPC
when sending bit ‘0’ to host. SPP in new PCs are hard driven
logic outputs which cannot be pulled low by RPC.
Bidirectional version of the hardware & software overcomes this
by using PS/2 Mode. In PS/2 Mode, Status Lines are used for Control
line input from RPC (RXR, TXA) and Printer Port Control Lines are
used to output the RPC Control signals (RXA & TXR). Default RPC
Dev Kit connector is setup for SPP mode. A PS/2 interface adapter
or cable is needed to use RPC Dev Kit in Bidirectional PS/2 mode.
(Refer to figure 1 on page 11 for wiring diagram).
In Bidirectional PS/2 mode, Printer port data lines can be used as
RPC data lines in bidirectional mode. Open collector / pull-up control
lines are not needed for RPC data lines.
Most of the new PCs come with Extended Capabilities Port (ECP). ECP
can be set to operate in PS/2 compatible bidirectional mode. Program
supplied with bidirectional version will automatically change the
mode from ECP to PS/2 and change it back to ECP when the RPC Dev Kit
software is closed.
|
name
|
pin
|
|
pin
|
bit
|
pin labels
|
| |
|
|
|
|
|
|
GND
|
1
|
|
18 to 25
|
|
Ground
|
|
D0
|
2
|
|
2
|
D0
|
Data 0
|
|
D1
|
3
|
|
3
|
D1
|
Data 1
|
|
D2
|
4
|
|
4
|
D2
|
Data 2
|
|
D3
|
5
|
|
5
|
D3
|
Data 3
|
|
TXR
|
6
|
|
1
|
C0
|
-Strobe
|
|
TXA
|
7
|
|
12
|
S5
|
+Paper Out
|
|
RXR
|
8
|
|
13
|
S4
|
+Printer Selected
|
|
RXA
|
9
|
|
14
|
C1
|
-Auto Linefeed
|
|
RES
|
10
|
|
16
|
C2
|
-Initialise Printer
|
|
5V
|
11
|
|
+5V supply
|
|
|
GND
|
12
|
|
0V supply
|
|
|
+ve interrupt
|
|
10
|
S6
|
-Acknowledge
|
PC printer port registers (addresses
given for base address of 0378)
| 0378
|
data register
|
b7
|
b6
|
b5
|
b4
|
b3
|
b2
|
b1
|
b0
|
| |
|
-
|
-
|
-
|
-
|
D3 |
D2 |
D1 |
D0 |
| |
| 0379
|
status register
|
b7
|
b6
|
b5
|
b4
|
b3
|
b2
|
b1
|
b0
|
| |
|
- |
Int |
TXA |
RXR |
- |
- |
- |
- |
| |
| 037A
|
control register
|
b7
|
b6
|
b5
|
b4
|
b3
|
b2
|
b1
|
b0
|
| |
|
-
|
-
|
dir
|
Ien
|
-
|
RES
|
RXA
|
TXR
|
For Extended Capabilities Port (ECP) only
| 077A |
Extended Control Register (ECR) |
b7 |
b6 |
b5 |
b4 |
b3 |
b2 |
b1 |
b0 |
| |
|
0 |
0 |
1 |
- |
- |
- |
- |
- |
Printer Port can be configured to operate in ECP mode by changing
the Printer Port setting in BIOS from SPP or EPP to ECP. BIOS setup
can be accessed by pressing DEL key for AWARD BIOS or F1 for
AMI BIOS when booting the computer. Parallel Port settings can be
changed in the Integrated Peripherals section of the BIOS setup
However, it may be necessary to change it back to SPP or EPP
mode for some printers to operate properly.
| int |
+ve transition interupt
bit, see "interupt drive" |
| Ien |
bit is internal interupt
enable, not used if polling used |
|
1 = interupt enable
, 0 = disabled (polled operation) |
|
|
| dir |
bit is internal,
controls direction of data output / input |
|
0 = data pins are
O/P's, ie drive data to RPC |
|
1 = data pins are
I/P's, ie read data from RPC |
|
|
| note |
RXA and TXR pins
are inverted drives from the register |
|
ie a 1 in the control
register gives a 0 on the pin |
|
all other registers
/ bits are true. |
Figure 1: RPCPS2CABLE (SPP to PS/2 Interface Cable wiring diagram
Appendix B
SAMPLE RPC DRIVE SUBROUTINES FOR A PIC HOST
These subroutines may by used by a PIC Host in the
RPC development PCB.
Packet transfers to / from the RPC are handled by two subroutines
:-
OUT_BYTE & IN_BYTE
Additionally LISTEN_BUS is called on completion of a packet transfer
to the RPC to return the data bus to inputs (default state).
| TITLE 'RPC
DRIVERS FOR A PIC' |
| SUBTITLE
'VERSION1 GRAHAM SHARPLES' |
|
list |
p=16C84 |
r=hex |
| ; |
| ;STANDARD
EQUATES - dedicated data file locations PAGE 0 |
| INDF |
EQU |
0 |
; INDIRECT
CALL , OPCODE WILL USE |
|
|
|
; FSR (04h) AS FILE POINTER |
| TMR |
EQU |
1 |
; 8 bit
timer |
| PCL |
EQU |
2 |
; low order
program counter |
| STATUS |
EQU |
3 |
; STATUS
BITS |
| IRP |
EQU |
7 |
; Not used
on 16c84, |
|
|
|
; indirect addressing
page bit |
| RP1 |
EQU |
6 |
; Not used
on 16c84 , high order |
|
|
|
; file addressing page
bit |
| RP0 |
EQU |
5 |
; file page,
0=PAGE 0 , 1=PAGE 1 |
|
|
|
; e.g. DDR's etc. |
| TO |
EQU |
4 |
; cleared
on watchdog time-out |
| PD |
EQU |
3 |
; cleared
on sleep instruction |
| Z |
EQU |
2 |
; ZERO flag |
| DC |
EQU |
1 |
; DIGIT
CARRY flag (4th bit) |
| C |
EQU |
0 |
; CARRY
flag |
| ; |
|
|
|
| FSR |
EQU |
4 |
; file pointer
|
|
|
|
; (indirect file address
register) |
| ; |
|
|
|
| PORTA |
EQU |
5 |
; i/o port
A - 5 Bits , Free for |
|
|
|
; applications program
use. |
| ; |
|
|
|
| RPC |
EQU |
06 |
; USE PORT
B ON PIC |
| ;
Bit assignments for RPC PORT |
| D7 |
EQU |
7 |
; Bi-Dir
data , D3 |
| D6 |
EQU |
6 |
; Bi-Dir
data , D2 |
| D5 |
EQU |
5 |
; Bi-Dir
data , D1 |
| D4 |
EQU |
4 |
; Bi-Dir
data , D0 |
| TXA |
EQU |
3 |
; INPUT
, active low TX accept from RPC |
| TXR |
EQU |
2 |
; OUTPUT
, active low TX request to RPC |
| RXA |
EQU |
1 |
; OUTPUT
, active low RX accept to RPC |
| RXR |
EQU |
0 |
; INPUT
, active low RX request fromRPC |
|
|
|
; (interrupt if required) |
| ; |
|
|
|
| PCLATH |
EQU |
0A |
; Holding reg for program
counter |
|
|
|
; high byte |
| INTCON |
EQU |
0B |
;GIE,EEIE,TOIE,INTE,RBIE,TOIF,INTF,
|
|
|
|
; RBIF interrupts. |
| ; STANDARD
EQUATES - dedicated data file locations - PAGE 1 |
| OPTION |
EQU |
81 |
; RBPU,INTEDG,RTS,RTE,PSA,PS2,PS1,PS0 |
| DDRA |
EQU |
85 |
; I/O direction reg ,portA
1= i/p 0= o/p |
| RPC_DDR |
EQU |
86 |
; Data direction register
for port B (RPC) |
|
|
|
; This register is in
BANK 1 of the register file. |
| ;-------------------------------------------------------------------- |
| ORG 0 |
|
|
|
| ONRESET |
GOTO |
START |
; jump to main program |
| ; |
|
|
|
| ; Initialise
PORT B to drive RPC. |
| START |
BSF |
STATUS,RP0 |
; select page 1 |
|
MOVLW |
B'11111001' |
; TXR & RXA O/P ,
Rest as inputs |
|
MOVWF |
RPC_DDR |
|
|
BCF |
STATUS,RP0 |
; select page 0 |
| ; |
|
|
|
| ; SUBROUTINE
- IN_BYTE |
| ; |
IN_BYTE -
READ A BYTE FROM THE RPC INTO FILE POINTED |
| ; |
|
TO BY FSR
W IS DESTROYED |
| ; |
|
|
|
| ; |
NOTE |
THIS ROUTINE
WILL HANG THE HOST UNTIL THE HOST |
|
|
COMPLETES
THE TRANSFER OF TWO NIBBLES |
|
|
|
|
| ; |
|
THIS SUBROUTINE
CAN BE CONFIGURES TO RUN |
| ; |
|
AS PART OF
AN INTERUPT HANDLER IF THE RXR |
| ; |
|
LINE FROM
THE RPC IS USED TO TRIGGER A HOST INTERUPT |
| ; |
|
|
|
| IN_BYTE |
BTFSC |
RPC,RXR |
; WE GOT A RX REQUEST
YET ? |
|
GOTO |
IN_BYTE |
; NO , SO LOOP BACK AND
WAIT |
|
|
|
|
| ; READ THE
LS NIBBLE FROM THE RPC |
|
BCF |
RPC,RXA |
; ACCEPT THE REQUEST
(SET ACCEPT LOW) |
| ; |
|
|
|
| AWAITDATA |
BTFSS |
RPC,RXR |
; HAS REQUEST GONE UP
? i.e. data is present |
|
GOTO |
AWAITDATA |
; LOOP BACK TILL IT DOES |
| ; |
|
|
|
|
NOP |
|
; TIME DELAY TO ENSURE
DATA STABLE |
|
|
|
; BEFOR READ |
|
MOVF |
RPC,W |
; READ THE LS NIBBLE
FROM THE BUS |
|
BSF |
RPC,RXA |
; TELL RPC WE GOT NIBBLE
(ACCEPT = 1) |
|
ANDLW |
B'11110000' |
; JUST THE DATA |
|
MOVWF |
INDF |
; SAVE LS NIBBLE IN TARGET
FILE (VIA FSR) |
|
SWAPF |
INDF,F |
; RIGHT JUSTIFY LS NIBBLE |
| ; |
|
|
|
| ; NOW GET
MS NIBBLE FROM THE RPC |
| INNIBBLE |
BTFSC |
RPC,RXR |
; WE GOT NEXT RX REQUEST
YET ? |
|
GOTO |
INNIBBLE |
; NO , SO LOOP BACK AND
WAIT |
| ; |
|
|
|
|
BCF |
RPC,RXA |
; ACCEPT REQUEST (SET
ACCEPT LOW) |
| ; |
|
|
|
| AWAITD1 |
BTFSS |
RPC,RXR |
; HAS REQUEST GONE UP
? i.e. data is present |
|
GOTO |
AWAITD1 |
; LOOP BACK TILL IT DOES |
| ; |
|
|
|
|
NOP |
|
; TIME DELAY TO ENSURE
DATA STABLE |
|
|
|
; BEFOR READ |
|
MOVF |
RPC,W |
; READ THE MS NIBBLE
FROM THE BUS |
|
BSF |
RPC,RXA |
; TELL RPC WE GOT NIBBLE
(ACCEPT = 1) |
|
ANDLW |
B'11110000' |
; JUST THE DATA |
|
IORWF |
INDF,F |
; COMBINE MS NIBBLE WITH
LS NIBBLE |
|
|
|
; ALREADY IN THE FILE
(VIA FSR) |
|
RETURN |
|
|
| ; A BYTE
HAS BEEN READ FROM THE RPC INTO ADDRESS POINTED AT BY FSR |
| ;-------------------------------------------------------------------- |
| ; SUBROUTINE-
OUT_BYTE |
| ; |
OUT_BYTE-
WRITE A BYTE FROM FILE POINTED TO BY FSR TO RPC |
| ; |
|
W IS DESTROYED |
| ; |
|
|
|
| ; |
NOTE |
THIS ROUTINE
WILL HANG THE HOST UNTIL THE RPC |
|
|
ACCEPTS THE
TRANSFER OF TWO NIBBLES |
| ; |
|
|
|
| ; |
WARNING -
OUT_BYTE WILL SET THE DATA BUS TO DRIVE |
| ; |
|
AFTER DETECTING |
| ; |
|
A TXA FROM
THE RPC. |
| ; |
|
THE CALLING
ROUTINE MUST SET 4 DATA LINES |
| ; |
|
BACK TO I/P |
|
| ; |
|
ON COMPLETION
OF PACKET TRANSFER |
| ; |
|
(i.e. call
LISTENBUS) |
| ; |
|
|
|
| OUT_BYTE |
SWAPF |
INDF,W |
; GET LS NIBBLE FROM
FILE (VIA FSR) INTO |
|
|
|
; BITS 4 to 7 of W |
|
ANDLW |
B'11110000' |
; JUST THE NIBBLE |
|
IORLW |
B'00000010' |
; SET TXR LOW, LEAVE
RXA HIGH |
|
MOVWF |
RPC |
; SET TXR LOW , OUTPUT
NIBBLE |
| ; |
|
|
|
| WACCEPT |
BTFSC |
RPC,TXA |
; WE GOT A TX ACCEPT
BACK YET ? |
|
GOTO |
WACCEPT |
; NO , SO LOOP BACK AND
WAIT |
| ; |
|
|
|
| ; WE GOT
ACCEPTANCE SO IT'S OK TO DRIVE BUS |
|
BSF |
STATUS,RP0 |
; SELECT PAGE 1 |
|
MOVLW |
B'00001001' |
; DRIVE BUS |
|
MOVWF |
RPC_DDR |
|
|
BCF |
STATUS,RP0 |
; SELECT PAGE 0 BUS IS
NOW DRIVING |
| ; |
|
|
|
|
BSF |
RPC,TXR |
; REMOVE REQUEST, DATA
IS ON BUS |
| WDUN |
BTFSS |
RPC,TXA |
; HAS DATA BEEN READ? |
|
GOTO |
WDUN |
; WAIT TILL RPC REMOVES
ACCEPT |
| ; |
|
|
|
