Datasheet

TLV5604
2.7-V TO 5.5-V 10-BIT 3-µS QUADRUPLE DIGITAL-TO-ANALOG CONVERTERS
WITH POWER DOWN
SLAS176B – DECEMBER 1997 – REVISED JULY 2002
23
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
APPLICATION INFORMATION
; DAC D next
; DAC D codes should be taken from 16 bytes (8 samples) further on in the sine table
; – this gives an inverted cosine function
MOV A,R7 ; pointer in R7
ADD A,#0FH ; add 15 – already done one INC
ANL A,#03FH ; wrap back round to 0 if > 64
MOV R7,A ; pointer back in R7
MOVC A,@A+DPTR ; get DAC D msb from the table
ORL A,#03H ; set control bits to DAC D address
B_LSB_TX:
JNB TI,B_LSB_TX ; wait for DAC B lsb transmit to complete
SETB T1 ; toggle FS
CLR T1
CLR TI ; clear for new transmit
MOV SBUF,A ; and send out the msb of DAC D
INC R7 ; increment the pointer in R7
MOV A,R7 ; to get the next byte from the table
MOVC A,@A+DPTR ; which is the lsb of this sample, now in ACC
D_MSB_TX:
JNB TI,D_MSB_TX ; wait for transmit to complete
CLR TI ; clear for new transmit
MOV SBUF,A ; and send out the lsb of DAC D
; increment the rolling pointer to point to the next sample
; ready for the next interrupt
MOV A,rolling_ptr
ADD A,#02H ; add 2 to the rolling pointer
ANL A,#03FH ; wrap back round to 0 if > 64
MOV rolling_ptr,A ; store in memory again
D_LSB_TX:
JNB TI,D_LSB_TX ; wait for DAC D lsb transmit to complete
CLR TI ; clear for next transmit
SETB T1 ; FS high
SETB T0 ; CS high
POP ACC
POP PSW
RETI
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; Stack needs definition
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RSEG STACK
DS 10h ; 16 Byte Stack!