''******************************************** ''* Full-Duplex Serial Driver v1.2 * ''* Author: Chip Gracey, Jeff Martin * ''* Copyright (c) 2006-2009 Parallax, Inc. * ''* See end of file for terms of use. * ''******************************************** {-----------------REVISION HISTORY----------------- v1.2 - 5/7/2009 fixed bug in dec method causing largest negative value (-2,147,483,648) to be output as -0. v1.1 - 3/1/2006 first official release. } VAR long cog 'cog flag/id long rx_head '9 contiguous longs long rx_tail long tx_head long tx_tail long rx_pin long tx_pin long rxtx_mode long bit_ticks long buffer_ptr byte rx_buffer[16] 'transmit and receive buffers byte tx_buffer[16] PUB start(rxpin, txpin, mode, baudrate) : okay '' Start serial driver - starts a cog '' returns false if no cog available '' '' mode bit 0 = invert rx '' mode bit 1 = invert tx '' mode bit 2 = open-drain/source tx '' mode bit 3 = ignore tx echo on rx stop longfill(@rx_head, 0, 4) longmove(@rx_pin, @rxpin, 3) bit_ticks := clkfreq / baudrate buffer_ptr := @rx_buffer okay := cog := cognew(@entry, @rx_head) + 1 PUB stop '' Stop serial driver - frees a cog if cog cogstop(cog~ - 1) longfill(@rx_head, 0, 9) PUB rxflush '' Flush receive buffer repeat while rxcheck => 0 PUB rxcheck : rxbyte '' Check if byte received (never waits) '' returns -1 if no byte received, $00..$FF if byte rxbyte-- if rx_tail <> rx_head rxbyte := rx_buffer[rx_tail] rx_tail := (rx_tail + 1) & $F PUB rxtime(ms) : rxbyte | t '' Wait ms milliseconds for a byte to be received '' returns -1 if no byte received, $00..$FF if byte t := cnt repeat until (rxbyte := rxcheck) => 0 or (cnt - t) / (clkfreq / 1000) > ms PUB rx : rxbyte '' Receive byte (may wait for byte) '' returns $00..$FF repeat while (rxbyte := rxcheck) < 0 PUB tx(txbyte) '' Send byte (may wait for room in buffer) repeat until (tx_tail <> (tx_head + 1) & $F) tx_buffer[tx_head] := txbyte tx_head := (tx_head + 1) & $F if rxtx_mode & %1000 rx PUB str(stringptr) '' Send string repeat strsize(stringptr) tx(byte[stringptr++]) PUB dec(value) | i, x '' Print a decimal number x := value == NEGX 'Check for max negative if value < 0 value := ||(value+x) 'If negative, make positive; adjust for max negative tx("-") 'and output sign i := 1_000_000_000 'Initialize divisor repeat 10 'Loop for 10 digits if value => i tx(value / i + "0" + x*(i == 1)) 'If non-zero digit, output digit; adjust for max negative value //= i 'and digit from value result~~ 'flag non-zero found elseif result or i == 1 tx("0") 'If zero digit (or only digit) output it i /= 10 'Update divisor PUB hex(value, digits) '' Print a hexadecimal number value <<= (8 - digits) << 2 repeat digits tx(lookupz((value <-= 4) & $F : "0".."9", "A".."F")) PUB bin(value, digits) '' Print a binary number value <<= 32 - digits repeat digits tx((value <-= 1) & 1 + "0") DAT '*********************************** '* Assembly language serial driver * '*********************************** org ' ' ' Entry ' entry mov t1,par 'get structure address add t1,#4 << 2 'skip past heads and tails rdlong t2,t1 'get rx_pin mov rxmask,#1 shl rxmask,t2 add t1,#4 'get tx_pin rdlong t2,t1 mov txmask,#1 shl txmask,t2 add t1,#4 'get rxtx_mode rdlong rxtxmode,t1 add t1,#4 'get bit_ticks rdlong bitticks,t1 add t1,#4 'get buffer_ptr rdlong rxbuff,t1 mov txbuff,rxbuff add txbuff,#16 test rxtxmode,#%100 wz 'init tx pin according to mode test rxtxmode,#%010 wc if_z_ne_c or outa,txmask if_z or dira,txmask mov txcode,#transmit 'initialize ping-pong multitasking ' ' ' Receive ' receive jmpret rxcode,txcode 'run a chunk of transmit code, then return test rxtxmode,#%001 wz 'wait for start bit on rx pin test rxmask,ina wc if_z_eq_c jmp #receive mov rxbits,#9 'ready to receive byte mov rxcnt,bitticks shr rxcnt,#1 add rxcnt,cnt :bit add rxcnt,bitticks 'ready next bit period :wait jmpret rxcode,txcode 'run a chuck of transmit code, then return mov t1,rxcnt 'check if bit receive period done sub t1,cnt cmps t1,#0 wc if_nc jmp #:wait test rxmask,ina wc 'receive bit on rx pin rcr rxdata,#1 djnz rxbits,#:bit shr rxdata,#32-9 'justify and trim received byte and rxdata,#$FF test rxtxmode,#%001 wz 'if rx inverted, invert byte if_nz xor rxdata,#$FF rdlong t2,par 'save received byte and inc head add t2,rxbuff wrbyte rxdata,t2 sub t2,rxbuff add t2,#1 and t2,#$0F wrlong t2,par jmp #receive 'byte done, receive next byte ' ' ' Transmit ' transmit jmpret txcode,rxcode 'run a chunk of receive code, then return mov t1,par 'check for head <> tail add t1,#2 << 2 rdlong t2,t1 add t1,#1 << 2 rdlong t3,t1 cmp t2,t3 wz if_z jmp #transmit add t3,txbuff 'get byte and inc tail rdbyte txdata,t3 sub t3,txbuff add t3,#1 and t3,#$0F wrlong t3,t1 or txdata,#$100 'ready byte to transmit shl txdata,#2 or txdata,#1 mov txbits,#11 mov txcnt,cnt :bit test rxtxmode,#%100 wz 'output bit on tx pin according to mode test rxtxmode,#%010 wc if_z_and_c xor txdata,#1 shr txdata,#1 wc if_z muxc outa,txmask if_nz muxnc dira,txmask add txcnt,bitticks 'ready next cnt :wait jmpret txcode,rxcode 'run a chunk of receive code, then return mov t1,txcnt 'check if bit transmit period done sub t1,cnt cmps t1,#0 wc if_nc jmp #:wait djnz txbits,#:bit 'another bit to transmit? jmp #transmit 'byte done, transmit next byte ' ' ' Uninitialized data ' t1 res 1 t2 res 1 t3 res 1 rxtxmode res 1 bitticks res 1 rxmask res 1 rxbuff res 1 rxdata res 1 rxbits res 1 rxcnt res 1 rxcode res 1 txmask res 1 txbuff res 1 txdata res 1 txbits res 1 txcnt res 1 txcode res 1 {{ ┌──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐ │ TERMS OF USE: MIT License │ ├──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┤ │Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation │ │files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, │ │modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software│ │is furnished to do so, subject to the following conditions: │ │ │ │The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.│ │ │ │THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE │ │WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR │ │COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, │ │ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. │ └──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘ }}