Author: sebastien.lelong
Date: Mon Sep 29 01:47:56 2008
New Revision: 334
Added:
trunk/unvalidated/include/peripheral/usart/serial_software.jal
trunk/unvalidated/sample/by_device/16f88/serial_sw_echo.jal
Log:
issue 8: serial_software lib integration + a simple echo sample
Added: trunk/unvalidated/include/peripheral/usart/serial_software.jal
==============================================================================
--- (empty file)
+++ trunk/unvalidated/include/peripheral/usart/serial_software.jal Mon Sep
29 01:47:56 2008
@@ -0,0 +1,361 @@
+-- Title: Software RS232 library
+-- Author: Stef Mientki, Copyright (c) 2002..2006, all rights reserved.
+-- Adapted-by: Sebastien Lelong.
+-- Compiler: >=2.4g
+--
+-- This file is part of jallib (http://jallib.googlecode.com)
+-- Released under the BSD license
(http://www.opensource.org/licenses/bsd-license.php)
+--
+-- Description: software RS232 library
+-- Library supports software RS232 send and receive procedure on any
IO-pin.
+-- Both the inverted and non-inverted routines are available,
+-- so it should fit any hardware.
+-- Baudrate can be set between 110 and 230_400 (for 20 Mhz Xtal),
+-- for lower Xtal frequencies the maximum baudrate will be equally lower.
+-- Baudrates are optimized, so even the high baudrates shouldn't be a
problem
+-- (my [Stef] standard = 115_200 Baud, which has never given me any
problems).
+-- Interrupts should be disabled during transmissions.
+-- Transmission parameters are 8 databits, 2 stopbits, no parity, no
handshake.
+--
+-- TODO: should transmission parameters be configurable ?
+-- (8 databits, 2 stopbits, no parity, no handshake)
+--
+
+
+procedure serial_sw_init() is
+ -- ouput/tx pin active or not according to invert
+ if serial_sw_invert then
+ serial_sw_tx_pin = high
+ else
+ serial_sw_tx_pin = low
+ end if
+end procedure
+
+
+;; Number of instructions per bit
+const _NINSTR = target_clock / (4 * serial_sw_baudrate)
+const _NINSTR2 = 5 + ( _NINSTR / 2)
+--
-----------------------------------------------------------------------------
+
+
+;; Transmit parameters
+const OL_TX = ( _NINSTR / ( 3 * 255 )) + 1
+const _IL_TX = ( ( _NINSTR - ( 4 * OL_TX ) ) - 16 ) / ( 3 * OL_TX )
+
+;; because some corrections have to be made, declare InnerLoop counter as
var
+var byte IL_TX = _IL_TX
+
+;; for small values, the value is truncated in stead of rounded, so add 1
+if _IL_TX < 10 then
+ IL_TX = _IL_TX + 1
+end if
+
+--
-----------------------------------------------------------------------------
+-- For Xtal = 20_000_000, the following counter values are calculated (in
Hex)
+-- Baud olcnt ilcnt Ninstr
+-- 110 3C FB
+-- 300 16 FA
+-- 600 0B FA
+-- 1200 06 E5
+-- 2400 03 E4
+-- 4800 02 A9
+-- 9600 01 A6
+-- 14_400 01 6D
+-- 19_200 01 50
+-- 38_400 01 24
+-- 57_600 01 16
+-- 115_200 01 08 43
+-- 230_400 01 01 22 NOT TESTED
+--
+-- Test sequence used: all possibilities
+
+
+
+-- receiving is optimized for 20 Mhz, 320_400 Baud
+-- Number of instructions = (3 * olval * Ilval) + (4 * olval) + 15
+-- 320kB ==> olval = ilval = 1
+-- next optimization for 20 Mhz, 115_200 Baud olval = 1
+-- olval = 1 ==> ilval = 8
+-- all other buadrates downto 1200 shouldnt be a problem now
+-- because of "IF-statement" this constant must be declared as a var
+
+var byte ilval
+var byte olval
+var byte ilval0
+
+if serial_sw_baudrate < 200_000 then
+ const _olval = ( _NINSTR / ( 3 * 255 )) + 1
+ const _ilval = ( ( _NINSTR - ( 4 * _olval ) ) - 15 ) / ( 3 * _olval )
+ const _ilval0 = ( ( _NINSTR2 - ( 4 * _olval ) ) - 5 ) / ( 3 * _olval )
+
+
+ ilval = _ilval
+ olval = _olval
+ ;due to rounding the next value can slightly below 1
+ if _ilval0 > 0 then
+ ilval0 = _ilval0
+ else
+ ilval0 = 1
+ end if
+ ilval0 = _ilval0
+
+ -- test if baudrate valid for the chosen Xtal frequency
+ if _olval > 255 then
+ pragma error -- baudrate too low for this Xtal
+ end if
+ if _olval == 0 then
+ pragma error -- baudrate too high for this Xtal
+ end if
+
+else
+ const _ilval = 1
+ const _olval = ((target_clock / (4 * serial_sw_baudrate)) - 15 ) / (4 +
3
* _ilval)
+ ilval = _ilval
+ olval = _olval
+
+end if
+
+-- For Xtal = 20_000_000, the following counter values are calculated (in
Hex)
+-- Baud olcnt ilcnt ILcnt0 Ninstr
+-- 110 3C FB 7C
+-- 300 16 FA 7C
+-- 600 0B FA 7C
+-- 1200 06 E5 72
+-- 2400 03 E4 72
+-- 4800 02 A9 55
+-- 9600 01 A7 55
+-- 14_400 01 6D 38
+-- 19_200 01 50 2A
+-- 38_400 01 25 14
+-- 57_600 01 16 0D
+-- 115_200 01 08 05 43
+-- 230_400 ? ? ? 22 NOT TESTED
+--
+-- Test sequence used (Hex)
+-- 01 02 04 08 10 20 40 80 00 FF AA 55
+
+
+
+-- Waits untill a character is received.
+-- Interrupts will be disabled during this routine, but restored
afterwards.
+-- Also here the code is doubled (inverting and non-inverting)
+-- and selection is done by a compiler-directive.
+procedure serial_sw_write(byte in data) is
+ var bit old_gie ;status of interrupt enable on entrance
+ ;; jallib(seb): this is a way to act on tx pin
+ ;;var bit pp at serial_sw_out_port : serial_sw_out_nr
+ var bit pp is serial_sw_tx_pin
+ var bit data_bit at data : 0
+
+ -- stop interrupts and be sure they are stopped
+ -- save old interrupt status
+ old_gie = INTCON_GIE
+ while INTCON_GIE loop
+ INTCON_GIE = false
+ end loop
+
+ if serial_sw_invert then
+ pp = low
+ _usec_delay((1_000_000/serial_sw_baudrate)-2)
+ for 8 loop
+ -- wait a whole bittime, less some usec for other
actions
+ pp = data_bit
+ data = data >> 1
+ _usec_delay((1_000_000/serial_sw_baudrate)-2)
+ end loop
+ -- add 2 stop bits
+ pp = high
+ _usec_delay((2_000_000/serial_sw_baudrate))
+
+ else
+ -- invert the data
+ data = ! data
+ pp = high
+ _usec_delay((1_000_000/serial_sw_baudrate)-2)
+ for 8 loop
+ -- wait a whole bittime, less some usec for other
actions
+ pp = data_bit
+ data = data >> 1
+ _usec_delay((1_000_000/serial_sw_baudrate)-2)
+ end loop
+ -- add 2 stop bits
+ pp = low
+ _usec_delay((2_000_000/serial_sw_baudrate))
+ end if
+
+ -- restore old interrupt status
+ INTCON_GIE = old_gie
+
+end procedure
+
+
+-- Waits untill a character is received.
+-- Interrupts will be disabled during this routine, but restored
afterwards.
+-- Also here the code is doubled (inverting and non-inverting)
+-- and selection is done by a compiler-directive.
+procedure serial_sw_read_wait(byte out data) is
+ var bit ie_old ;status of interrupt enable on entrance
+ var bit ready
+ ;; jallib(seb): this is a way to act on rx pin
+ ;;var bit pp at serial_sw_in_port : serial_sw_in_nr
+ var bit pp is serial_sw_rx_pin
+
+ -- stop interrupts and be sure they are stopped
+ -- save old interrupt status
+ ie_old = INTCON_GIE
+ while INTCON_GIE loop
+ INTCON_GIE = false
+ end loop
+
+ if serial_sw_invert then
+ -- wait for serial line inactive
+ while !pp loop end loop
+
+ ready = false
+ while !ready loop
+ -- wait for startbit
+ while pp loop end loop
+
+ -- wait half a bit time, less 5 usec for other actions
+ _usec_delay((1_000_000/(2*serial_sw_baudrate))-1)
+
+ -- test if still startbit, otherwise restart
+ if !pp then
+ -- now fetch 8 bits
+ for 8 loop
+ -- wait a whole bittime, less 5 usec
for other actions
+
_usec_delay((1_000_000/serial_sw_baudrate)-1)
+ -- shift new bit in
+ data = data >> 1
+ if pp then
+ data = data | 0x80
+ end if
+ end loop
+ ready = true
+ else
+ ready = false
+ end if
+ end loop
+ else ;NOT inverted
+ -- wait for serial line inactive
+ while pp loop end loop
+
+ ready = false
+ while !ready loop
+ -- wait for startbit
+ while !pp loop end loop
+
+ -- wait half a bit time, less 5 usec for other actions
+ _usec_delay((1_000_000/(2*serial_sw_baudrate))-1)
+
+ -- test if still startbit, otherwise restart
+ if pp then
+ -- now fetch 8 bits
+ for 8 loop
+ -- wait a whole bittime, less 5 usec
for other actions
+
_usec_delay((1_000_000/serial_sw_baudrate)-1)
+ -- shift new bit in
+ data = data >> 1
+ if !pp then
+ data = data | 0x80
+ end if
+ end loop
+ ready = true
+ else
+ ready = false
+ end if
+ end loop
+ end if
+
+ -- restore old interrupt status
+ INTCON_GIE = ie_old
+
+end procedure
+
+
+--
-----------------------------------------------------------------------------
+-- Here the serial_sw_write procedure is declared as a pseudo variable
+-- so you can use it in the following way:
+-- {{{
+-- serial_sw_write = 0x33
+-- }}}
+procedure serial_sw_data'put(byte in data) is
+ serial_sw_write(data)
+end procedure
+
+-- Here the serial_sw_read_wait procedure is declared as a pseudo variable
+-- so you can use it in the following way
+-- {{{
+-- Data = serial_sw_write
+-- }}}
+function serial_sw_data'get() return byte is
+ var byte data
+ serial_sw_read_wait( data )
+ return data
+end function
+
+-- Waits untill a character is received or time out is reached.
+-- Interrupts will be disabled during this routine, but restored
afterwards.
+-- Also here the code is doubled (inverting and non-inverting)
+-- and selection is done by a compiler-directive.
+function serial_sw_read(byte out data) return bit is
+ var bit ie_old ;status of interrupt enable on entrance
+ ;; jallib(seb): this is a way to act on rx pin
+ ;;var bit pp at serial_sw_in_port : serial_sw_in_nr
+ var bit pp is serial_sw_rx_pin
+
+ if serial_sw_invert != pp then
+ return false
+ end if
+
+ -- stop interrupts and be sure they are stopped
+ -- save old interrupt status
+ ie_old = INTCON_GIE
+ while INTCON_GIE loop
+ INTCON_GIE = false
+ end loop
+
+ if serial_sw_invert then
+ -- wait for startbit
+ while pp loop end loop
+
+ -- wait half a bit time, less 5 usec for other actions
+ _usec_delay((1_000_000/(2*serial_sw_baudrate))-1)
+
+ -- now fetch 8 bits
+ for 8 loop
+ -- wait a whole bittime, less 5 usec for other actions
+ _usec_delay((1_000_000/serial_sw_baudrate)-1)
+ -- shift new bit in
+ data = data >> 1
+ if pp then
+ data = data | 0x80
+ end if
+ end loop
+ else ;NOT inverted
+ -- wait for startbit
+ while !pp loop end loop
+
+ -- wait half a bit time, less 5 usec for other actions
+ _usec_delay((1_000_000/(2*serial_sw_baudrate))-1)
+
+ -- now fetch 8 bits
+ for 8 loop
+ -- wait a whole bittime, less 5 usec for other actions
+ _usec_delay((1_000_000/serial_sw_baudrate)-1)
+ -- shift new bit in
+ data = data >> 1
+ if !pp then
+ data = data | 0x80
+ end if
+ end loop
+ end if
+
+ -- restore old interrupt status
+ INTCON_GIE = ie_old
+
+ return true
+
+end function
+
+
Added: trunk/unvalidated/sample/by_device/16f88/serial_sw_echo.jal
==============================================================================
--- (empty file)
+++ trunk/unvalidated/sample/by_device/16f88/serial_sw_echo.jal Mon Sep 29
01:47:56 2008
@@ -0,0 +1,58 @@
+-- Title: Sample using software implemented USART.
+-- Author: Sebastien Lelong, Copyright (c) 2008, all rights reserved.
+-- Adapted-by:
+-- Compiler: >=2.4g
+--
+-- This file is part of jallib (http://jallib.googlecode.com)
+-- Released under the BSD license
(http://www.opensource.org/licenses/bsd-license.php)
+--
+-- Description: this sample shows how to setup a simple software serial
communication link.
+-- It echoes every received char.
+--
+
+-- select chip
+include 16f88
+-- set all IO as digital
+enable_digital_io()
+
+-- We'll use internal oscillator. It work @ 8MHz
+pragma target clock 8_000_000
+pragma target OSC INTOSC_NOCLKOUT
+-- no watchdog, please
+pragma target WDT disabled
+
+-- ok, now setup serial
+-- setup speed. Standard values are: 57_600, 19_200, 9_600, 2_400, ...
+-- Note: as it's a software implementation, not all baudrates can work with
+-- our 8MHz clock. For instance, 19200 gives too much errors. We'll a lower
+-- baudrate here.
+const serial_sw_baudrate = 2_400
+-- because it's a software implementation, we also need to define
+-- tx and rx pins. How clever we are: we use the same pin as in hardware,
+-- so it works out of the box with any board having an USART module...
+var volatile bit serial_sw_tx_pin is pin_B5
+var volatile bit serial_sw_rx_pin is pin_B2
+-- and we also need to specify direction
+pin_B5_direction = output
+pin_B2_direction = input
+-- finally, how levels are understood ? Inverted or not ?
+-- Note in hardware serial, it's inverted. Since we're talking to a PC
+-- we need to invert the signal
+const serial_sw_invert = true
+-- now we can use serial_software module
+include serial_software
+-- initialize the whole with our parameters
+serial_sw_init()
+
+-- inform user PIC is ready !
+serial_sw_write("!")
+
+-- let's build our loop
+var byte char -- will store received char
+forever loop
+ if serial_sw_read(char)
+ then
+ serial_sw_write(char) -- that's the echo...
+ end if
+end loop
+
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