beautypg.com

Texas Instruments TLV1562 User Manual

Page 19

background image

Conversation Between the TLV1562 and the DSP

13

Interfacing the TLV1562 Parallel ADC to the TMS320C54x DSP

Table 7. DSP Algorithm for Mono Interrupt Driven Mode Using RD

Wait cycles for the DSP internally (40 MHz DSPCLK):

STEPS

TIMING, NOTES

APD=0

ADCSYCLK

= 7.5 MHz

APD=0

ADCSYCLK

= 10 MHz

APD=1

ADCSYCLK

= 10 MHz

APD=1

ADCSYCLK

= 10 MHz

0.

Initialization

Write all configuration data to the
ADC

activate the mono interrupt-driven mode
in CR0(2;3)

1.

set CS

deselect ADC (optional with APD=0)

2.

clear CS

Select ADC
(Note: if Hardware Auto power down is
enabled, Chip select has to be used,
otherwise CS can be left high)

3.

Wait for
t

D(CSL-sample)

+1ADCSYSCLK

t

D(CSL-sample)

= 5ns (APD=0)

t

D(CSL-sample)

= 500ns (APD=1)

6

5

26

25

4.

Clear RD

ADC goes over from sampling into
conversion

5.

Wait until INT goes low

alternative: ignore the INT signal, wait 49
ns+5(6) ADCSYSCLK and goto step
number 7

34

22

34

22

6.

Wait the time t

EN(DATAOUT)

t

EN(DATAOUT)

= 41 ns

2

2

2

2

7.

Read sample out from the data port;
Reset RD signal

8.

Goto step 1 or step 3 (if APD=0) for
more samples