| ??? 01/31/07 18:15 Read: times Msg Score: +1 +1 Good Answer/Helpful |
#131821 - Full code for reference if anyone's interested Responding to: ???'s previous message |
Please excuse any typos in the comments - it's been a long day.
;
; Starting with ATMEL 89C51ED2 and SPI
;
; LED on port 22 on wait 1 second
; LED on port 23 on wait one second
; LED on port 22 off wait one second
; LED on port 23 off wait one second
; Oh, the excitement!
;
$NOMOD
$TITLE(BYTE SPI_TEST)
$DEBUG
$OBJECT
$NOPAGING
;Variable declarations
$include(C:\asm51\89C51ED2.inc)
SS EQU P2.1 ;J7-29
rec_data Data 30h
T1COUNT Data 31h ;Timer 1 count
trans_completed Bit 00h
ALARM1 Bit 01h ;Flag for timer 1 set in timer 1 interrupt
;++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
;
; Macros
START_50MS_TIMER MACRO FIFTY_MS_INTERVALS ;FIFTY_MS_INTERVALS is the
;number of .05 second
;intervals to wait for
clr ET1
clr alarm1
orl TMOD,#10h ;Set timer 1 to 16-bit mode
MOV TH1,#0B0H
MOV TL1,#03CH ;Initialize TL1 to overflow every .05 seconds
SETB ET1 ;Enable timer interrupt 1
SETB EA ;Enable all interrupts
MOV T1COUNT, FIFTY_MS_INTERVALS ;Set T1COUNT to 20 to wait for 1s
SETB TR1 ;Turn timer 0 on
ENDM
;
; End of Macros
;++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
org 0000H
ljmp MAIN
ORG 001Bh
ljmp T1_INTERRUPT ;Timer 1 interrupt
org 4Bh
ljmp SPI_INT
org 100h
MAIN:
orl spcon, #10h
setb SS
orl spcon, #82h
anl spcon, #0F7h ;cpol = 0
mov a, spcon
clr acc.2
mov spcon, a
orl ien1, #04h
orl spcon, #40h
clr trans_completed
setb ea
;//////////////////////////////////////////////////////////////////////////////
;
; Set up MAX6957 registers
;
clr SS
mov SPDAT,#04h ; config register
jnb trans_completed,$ ; /* wait end of transmission */
clr trans_completed ; /* clear software transfer flag */
mov SPDAT,#01h ; disable shutdown, global current control, trans det disabled
jnb trans_completed,$ ; /* wait end of transmission */
clr trans_completed ; /* clear software transfer flag */
setb SS ; read 2 bytes into SPI slave
nop ; min CS pulse is 19 ns so at 12 MHz one nop should do it
clr SS
mov SPDAT,#0Dh ; ports 20, 21, 22, 23 config register
jnb trans_completed,$ ; /* wait end of transmission */
clr trans_completed ; /* clear software transfer flag */
mov SPDAT,#0Ch ; set port 22 & 23 to LED Driver
jnb trans_completed,$ ; /* wait end of transmission */
clr trans_completed ; /* clear software transfer flag */
setb SS ; read 2 bytes into SPI slave
nop ; min CS pulse is 19 ns so at 12 MHz one nop should do it
;//////////////////////////////////////////////////////////////////////////////
;
; Main loop
;
LOOP1:
clr SS
mov SPDAT,#36h ; port 22
jnb trans_completed,$ ; /* wait end of transmission */
clr trans_completed ; /* clear software transfer flag */
mov SPDAT,#01h ; on
jnb trans_completed,$ ; /* wait end of transmission */
clr trans_completed ; /* clear software transfer flag */
setb SS
nop ; min CS pulse is 19 ns so at 12 MHz one nop should do it
START_50MS_TIMER #20 ;Delay for 20 * .05 seconds
jnb Alarm1, $
clr SS
mov SPDAT,#37h ; port 22
jnb trans_completed,$ ; /* wait end of transmission */
clr trans_completed ; /* clear software transfer flag */
mov SPDAT,#01h ; on
jnb trans_completed,$ ; /* wait end of transmission */
clr trans_completed ; /* clear software transfer flag */
setb SS
nop ; min CS pulse is 19 ns so at 12 MHz one nop should do it
START_50MS_TIMER #20 ;Delay for 20 * .05 seconds
jnb Alarm1, $
clr SS
mov SPDAT,#36h ; port 22
jnb trans_completed,$ ; /* wait end of transmission */
clr trans_completed ; /* clear software transfer flag */
mov SPDAT,#00h ; off
jnb trans_completed,$ ; /* wait end of transmission */
clr trans_completed ; /* clear software transfer flag */
setb SS
nop ; min CS pulse is 19 ns so at 12 MHz one nop should do it
START_50MS_TIMER #20 ;Delay for 20 * .05 seconds
jnb Alarm1, $
clr SS
mov SPDAT,#37h ; port 23
jnb trans_completed,$ ; /* wait end of transmission */
clr trans_completed ; /* clear software transfer flag */
mov SPDAT,#00h ; off
jnb trans_completed,$ ; /* wait end of transmission */
clr trans_completed ; /* clear software transfer flag */
setb SS
START_50MS_TIMER #20 ;Delay for 20 * .05 seconds
jnb Alarm1, $
jmp loop1 ; endless loop
;++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
;
;
; Timer1 interrupt. Timer 1 used for multiples of .05 seconds.
T1_INTERRUPT:
MOV TH1,#03CH
MOV TL1,#0B0H
DJNZ T1COUNT,T1_EXIT ;If we haven't reached 0 then jump out of int routine
SETB ALARM1
CLR ET1 ;stop timer
CLR TR1
T1_EXIT:
RETI
;
; End of Timer1 interrupt
;++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
;++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
;
;
; SPI interrupt.
SPI_INT: ; /* interrupt address is 0x004B */
mov R7,SPSTA
mov ACC,R7
jnb ACC.7,BREAK1 ;case 0x80:
mov rec_data,SPDAT ; /* read receive data */
setb trans_completed ; /* set software flag */
BREAK1:
jnb ACC.4,BREAK2 ;case 0x10:
cpl p2.0 ;J7-31 ; Debugging
; /* put here for mode fault tasking */
BREAK2:
jnb ACC.6,BREAK3 ;case 0x40:
cpl p2.0 ;J7-31 ; Debugging
; /* put here for overrun tasking */
BREAK3:
RETI
;
; End of SPI interrupt
;++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
END
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