Datasheet

TLV5614
2.7-V TO 5.5-V 12-BIT 3-µS QUADRUPLE DIGITAL-TO-ANALOG CONVERTERS
WITH POWER DOWN
SLAS188B – SEPTEMBER 1998 – REVISED APRIL 2003
19
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
APPLICATION INFORMATION
next idle ;wait for interrupt
b next
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; all else fails stop here
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done b done ;hang there
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; Interrupt Service Routines
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int1 ret ; do nothing and return
int23 ret ; do nothing and return
timer_isr:
in iosr_stat, IOSR; store IOSR value into variable space
lacl iosr_stat ; load acc with iosr status
and #0FFFDh ; reset IO1 – LDAC low
sacl temp ;
out temp, IOSR ;
or #0002h ; set IO1 – LDAC high
sacl temp ;
out temp, IOSR ;
and #0FFFEh ; reset IO0 – CS low
sacl temp ;
out temp, IOSR ;
lacl r_ptr ; load rolling pointer to accumulator
add #sinevals ; add pointer to table start
sacl DACa_ptr ; to get a pointer for next DAC a sample
add #08h ; add 8 to get to DAC C pointer
sacl DACc_ptr
add #08h ; add 8 to get to DAC B pointer
sacl DACb_ptr
add #08h ; add 8 to get to DAC D pointer
sacl DACd_ptr
mar *,ar0 ; set ar0 as current AR
; DAC A
lar ar0, DACa_ptr ; ar0 points to DAC a sample
lacl * ; get DAC a sample into accumulator
or #DACa_control ; OR in DAC A control bits
sacl temp ;
out temp, SDTR ; send data
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; We must wait for transmission to complete before writing next word to the SDTR.;
TLV5614/04 interface does not allow the use of burst mode with the full packet; rate, as
we need a CLKX –ve edge to clock in last bit before FS goes high again,; to allow SPI
compatibility.
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rpt #016h ; wait long enough for this configuration
nop ; of MCLK/CLKOUT1 rate
; DAC B
lar ar0, dacb_ptr ; ar0 points to DAC a sample
lacl * ; get DAC a sample into accumulator
or #DACb_control ; OR in DAC B control bits
sacl temp ;
out temp, SDTR ; send data
rpt #016h ; wait long enough for this configuration
nop ; of MCLK/CLKOUT1 rate
; DAC C
lar ar0, dacc_ptr ; ar0 points to dac a sample
lacl * ; get DAC a sample into accumulator
or #DACc_control ; OR in DAC C control bits
sacl temp ;
out temp, SDTR; send data
rpt #016h ; wait long enough for this configuration
nop ; of MCLK/CLKOUT1 rate