TLC32040C, TLC32040I, TLC32041C, TLC32041I

ANALOG INTERFACE CIRCUITS

SLAS014E – SEPTEMBER 1987 – REVISED MAY 1995

15

POST OFFICE BOX 655303

asynchronous operation — more than one receive frame sync occurring between two receive frame syncs

When incrementally adjusting the conversion period via the A + A’ or A – A’ register options, a specific protocol

is followed. For both transmit and receive conversion periods, the incremental conversion period adjustment

is performed near the end of the conversion period. The command to use the incremental conversion period

adjust options is sent to the AIC during a FSX frame sync. The ongoing transmit conversion period is then

adjusted. However, three possibilities exist for the receive conversion period adjustment in the diagram as

shown in the following figure. If the adjustment command is issued during transmit conversion period A, receive

can be ignored if the adjustment command is sent during a receive conversion period, which is already being

or is adjusted due to a prior adjustment command. For example, if adjustment commands are issued during

transmit conversion periods A, B, and C, the first two commands can cause receive conversion periods A and

B to be adjusted, while the third receive adjustment command is ignored. The third adjustment command is

ignored since it was issued during receive conversion period B, which already is adjusted via the transmit

conversion period B adjustment command.

Transmit

Conversion

Period A

Receive Conversion Period A

FSX

FSR

Transmit

Conversion

Period B

Transmit

Conversion

Period C

t1

t2

Receive Conversion Period B

asynchronous operation — more than one set of primary and secondary DX serial communication occurring

between two receive frame sync (see AIC DX data word format section)

The TA, TA’, TB, and control register information that is transmitted in the secondary communications is always

receive conversion period A. Otherwise, this information is applied during receive conversion period B. If RA,

RA’, and RB register information has already been received and is being applied during an ongoing conversion

period, any subsequent RA, RA’, or RB information that is received during this receive conversion period is

disregarded (see diagram below).

FSX

FSR

Transmit

Conversion

Period A

Transmit

Conversion

Period B

Transmit

Conversion

Period C

t1

t2

Primary

Secondary

Primary

Secondary

Primary

Secondary

Receive Conversion

Period A

Receive Conversion Period B