diff options
Diffstat (limited to 'bootloader/com-16f887-uart.inc')
| -rw-r--r-- | bootloader/com-16f887-uart.inc | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/bootloader/com-16f887-uart.inc b/bootloader/com-16f887-uart.inc new file mode 100644 index 0000000..b9d05b2 --- /dev/null +++ b/bootloader/com-16f887-uart.inc @@ -0,0 +1,75 @@ + ;; + ;; spreadspace pic utils + ;; + ;; + ;; Copyright (C) 2011 Christian Pointner <equinox@spreadspace.org> + ;; + ;; This file is part of spreadspace pic utils. + ;; + ;; spreadspace pic utils is free software: you can redistribute it and/or modify + ;; it under the terms of the GNU General Public License as published by + ;; the Free Software Foundation, either version 3 of the License, or + ;; any later version. + ;; + ;; spreadspace pic utils is distributed in the hope that it will be useful, + ;; but WITHOUT ANY WARRANTY; without even the implied warranty of + ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + ;; GNU General Public License for more details. + ;; + ;; You should have received a copy of the GNU General Public License + ;; along with spreadspace pic utils. If not, see <http://www.gnu.org/licenses/>. + ;; + + ;; --- transmit byte and add it to csum +com_tx_byte + btfss PIR1,TXIF + goto com_tx_byte + movwf TXREG + xorwf csum,f + return + + ;; ---- wait for byte to be received +com_rx_byte + btfsc RCSTA,OERR + goto uart_rx_oe + btfss PIR1,RCIF + goto com_rx_byte + btfsc RCSTA,FERR + goto uart_rx_fe + movf RCREG,w + return + +uart_rx_oe ; recover from overflow + bcf RCSTA,CREN + bsf RCSTA,CREN + goto com_rx_byte + +uart_rx_fe ; recover from framing error + movf RCREG,w + goto com_rx_byte + + ;; ----- initialize com (not a subroutine, com_init is called by generic_init +com_init + ;; bank 3 + bsf STATUS,RP0 + bsf STATUS,RP1 + movlw b'00001000' ; TX non-inverted, 16bit Baudrate, no auto baud detect + ;; movlw b'00011000' ; TX inverted, 16bit Baudrate, no auto baud detect + movwf BAUDCTL + + ;; bank 1 + bcf STATUS,RP1 + movlw b'01110000' ; set internal OSC to 8MHz + movwf OSCCON + movlw b'00100100' ; Baudrate = High Speed, async mode, transmit enabled, 8bit + movwf TXSTA + movlw .34 ; Baudrate = 57600 (@ 8MHz) -> -0,79 % Error + ;; movlw .51 ; Baudrate = 38400 (@ 8MHz) -> -0,002 % Error + ;; movlw .103 ; Baudrate = 19200 (@ 8MHz) -> 0,16 % Error + movwf SPBRG + clrf SPBRGH + + ;; bank 0 + bcf STATUS,RP0 + movlw b'10010000' ; enable Serial Port, 8bit, enable continues receive, disable address detection + movwf RCSTA |