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[/] [openmsp430/] [trunk/] [fpga/] [xilinx_diligent_s3board/] [software/] [ta_uart/] [swuart.s] - Blame information for rev 211

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#include "hardware.h"
 
;variables
.data
;        .comm   rxdata,1,1              ;char var
        .comm   rxshift,1,1             ;char var
        .comm   rxbit,2,2               ;short var, aligned
 
.text
 
;interrupt(TIMERA0_VECTOR)               ;register interrupt vector
;interrupt handler to receive as Timer_A UART
.global ccr0                            ;place a label afterwards so
ccr0:                                   ;that it is used in the listing
        add     &rxbit, r0
        jmp     .Lrxstart               ;start bit
        jmp     .Lrxdatabit             ;D0
        jmp     .Lrxdatabit             ;D1
        jmp     .Lrxdatabit             ;D2
        jmp     .Lrxdatabit             ;D3
        jmp     .Lrxdatabit             ;D4
        jmp     .Lrxdatabit             ;D5
        jmp     .Lrxdatabit             ;D6
;        jmp     .Lrxlastbit             ;D7 that one is following anyway
 
.Lrxlastbit:                            ;last bit, handle byte
        bit     #SCCI, &CCTL0           ;read last bit
        rrc.b   &rxshift                 ;and save it
        clr     &rxbit                   ;reset state
        mov     #CCIE|CAP|CM_2|CCIS_1|SCS, &CCTL0   ;restore capture mode
;        mov.b   &rxshift, &rxdata         ;copy received data
;        bic     #CPUOFF|OSCOFF|SCG0|SCG1, 0(r1) ;exit all lowpower modes
        ;here you might do other things too, like setting a flag
        ;that the wakeup comes from the Timer_A UART. however
        ;it should not take longer than one bit time, otherwise
        ;charcetrs will be lost.
;        reti
        mov.b   &rxshift, r15           ;return received data
        ret
 
.Lrxstart:                              ;startbit, init
        clr     &rxshift                 ;clear input buffer
        add     #(BAUD/2), &CCR0        ;startbit + 1.5 bits -> first bit
        mov     #CCIE|CCIS_1|SCS, &CCTL0;set compare mode, sample bits
        jmp     .Lrxex                  ;set state,...
 
.Lrxdatabit:                            ;save databit
        bit     #SCCI, &CCTL0           ;measure databit
        rrc.b   &rxshift                 ;rotate in databit
 
.Lrxex: add     #BAUD, &CCR0            ;one bit delay
        incd    &rxbit                  ;setup next state
;        reti
        mov     #0xffff, r15            ;return 0xffff
        ret
 
; void serPutc(char)
;use an other Capture/Compare than for receiving (full duplex).
;this one is without interrupts and OUTMOD, because only
;this way P1.1 can be used. P1.1 is prefered because the
;BSL is on that pin too.
.global putchar
        .type putchar, @function
putchar:                                ;send a byte
        mov     #0, &CCTL1              ;select compare mode
        mov     #10, r13                ;ten bits: Start, 8 Data, Stop
        rla     r15                     ;shift in start bit (0)
        bis     #0x0200, r15            ;set tenth bit (1), thats the stop bit
        mov     &TAR, &CCR1             ;set up start time
.Lt1lp: add     #BAUD, &CCR1            ;set up for one bit
        rrc     r15                     ;shift data trough carry
        jc      .Lt1                    ;test carry bit
.Lt0:   bic.b   #TX, &P1OUT             ;generate pulse
        jmp     .Ltc                    ;
.Lt1:   bis.b   #TX, &P1OUT             ;just use the same amount of time as for a zero
        jmp     .Ltc                    ;
.Ltc:   bit     #CCIFG, &CCTL1          ;wait for compare
        jz      .Ltc                    ;loop until the bit is set
        bic     #CCIFG, &CCTL1          ;clear for next loop
        dec     r13                     ;decrement bit counter
        jnz     .Lt1lp                  ;loop until all bits are transmitted
        ret

Line No.	Rev	Author	Line
1	143	olivier.gi
2	2	olivier.gi	`#include "hardware.h"`
3
4			`;variables`
5			`.data`
6	153	olivier.gi	`; .comm rxdata,1,1 ;char var`
7	2	olivier.gi	`.comm rxshift,1,1 ;char var`
8			`.comm rxbit,2,2 ;short var, aligned`
9
10			`.text`
11
12	143	olivier.gi	`;interrupt(TIMERA0_VECTOR) ;register interrupt vector`
13	2	olivier.gi	`;interrupt handler to receive as Timer_A UART`
14			`.global ccr0 ;place a label afterwards so`
15			`ccr0: ;that it is used in the listing`
16	143	olivier.gi	`add &rxbit, r0`
17	2	olivier.gi	`jmp .Lrxstart ;start bit`
18			`jmp .Lrxdatabit ;D0`
19			`jmp .Lrxdatabit ;D1`
20			`jmp .Lrxdatabit ;D2`
21			`jmp .Lrxdatabit ;D3`
22			`jmp .Lrxdatabit ;D4`
23			`jmp .Lrxdatabit ;D5`
24			`jmp .Lrxdatabit ;D6`
25			`; jmp .Lrxlastbit ;D7 that one is following anyway`
26
27			`.Lrxlastbit: ;last bit, handle byte`
28			`bit #SCCI, &CCTL0 ;read last bit`
29	143	olivier.gi	`rrc.b &rxshift ;and save it`
30			`clr &rxbit ;reset state`
31	2	olivier.gi	`mov #CCIE\|CAP\|CM_2\|CCIS_1\|SCS, &CCTL0 ;restore capture mode`
32	153	olivier.gi	`; mov.b &rxshift, &rxdata ;copy received data`
33			`; bic #CPUOFF\|OSCOFF\|SCG0\|SCG1, 0(r1) ;exit all lowpower modes`
34	2	olivier.gi	`;here you might do other things too, like setting a flag`
35			`;that the wakeup comes from the Timer_A UART. however`
36			`;it should not take longer than one bit time, otherwise`
37			`;charcetrs will be lost.`
38	153	olivier.gi	`; reti`
39			`mov.b &rxshift, r15 ;return received data`
40			`ret`
41	2	olivier.gi
42			`.Lrxstart: ;startbit, init`
43	143	olivier.gi	`clr &rxshift ;clear input buffer`
44	2	olivier.gi	`add #(BAUD/2), &CCR0 ;startbit + 1.5 bits -> first bit`
45			`mov #CCIE\|CCIS_1\|SCS, &CCTL0;set compare mode, sample bits`
46			`jmp .Lrxex ;set state,...`
47
48			`.Lrxdatabit: ;save databit`
49			`bit #SCCI, &CCTL0 ;measure databit`
50	143	olivier.gi	`rrc.b &rxshift ;rotate in databit`
51	2	olivier.gi
52			`.Lrxex: add #BAUD, &CCR0 ;one bit delay`
53	153	olivier.gi	`incd &rxbit ;setup next state`
54			`; reti`
55			`mov #0xffff, r15 ;return 0xffff`
56			`ret`
57	2	olivier.gi
58			`; void serPutc(char)`
59			`;use an other Capture/Compare than for receiving (full duplex).`
60			`;this one is without interrupts and OUTMOD, because only`
61			`;this way P1.1 can be used. P1.1 is prefered because the`
62			`;BSL is on that pin too.`
63			`.global putchar`
64			`.type putchar, @function`
65			`putchar: ;send a byte`
66			`mov #0, &CCTL1 ;select compare mode`
67			`mov #10, r13 ;ten bits: Start, 8 Data, Stop`
68			`rla r15 ;shift in start bit (0)`
69			`bis #0x0200, r15 ;set tenth bit (1), thats the stop bit`
70			`mov &TAR, &CCR1 ;set up start time`
71			`.Lt1lp: add #BAUD, &CCR1 ;set up for one bit`
72			`rrc r15 ;shift data trough carry`
73			`jc .Lt1 ;test carry bit`
74			`.Lt0: bic.b #TX, &P1OUT ;generate pulse`
75			`jmp .Ltc ;`
76			`.Lt1: bis.b #TX, &P1OUT ;just use the same amount of time as for a zero`
77			`jmp .Ltc ;`
78			`.Ltc: bit #CCIFG, &CCTL1 ;wait for compare`
79			`jz .Ltc ;loop until the bit is set`
80			`bic #CCIFG, &CCTL1 ;clear for next loop`
81			`dec r13 ;decrement bit counter`
82			`jnz .Lt1lp ;loop until all bits are transmitted`
83			`ret`

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Subversion Repositories openmsp430

[/] [openmsp430/] [trunk/] [fpga/] [xilinx_diligent_s3board/] [software/] [ta_uart/] [swuart.s] - Blame information for rev 211