TXZ Family
Serial Peripheral Interface
2019-02-28
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Rev. 3.0
3.3.7. Special control
3.3.7.1. Polarity of TSPIxCS0/1/2/3 signal and generation timing
The polarity of TSPIxCS0/1/2/3 can be individually selected by
[TSPIxFMTR0]
<CSnPOL>(polarity register of
TSPIxCS0/1/2/3/). In the case of
[TSPIxFMTR0]
<CSnPOL>=0, it becomes negative logic and
[TSPIxFMTR0]
<CSnPOL>=1, it becomes positive logic.
Moreover, the generating timing of TSPIxCS0/1/2/3 can be set up as follows.
(1) Serial clock delay
“t
a
” is a delay time from the time when TSPIxCS0/1/2/3 is asserted until the transmit clock (TSPIxSCK)
changes. To set a serial clock delay time, set
[TSPIxFMTR0]
<CSSCKDL>.
(2) TSPIxCS0/1/2/3/ deassert delay
“t
b
” is a delay time from the time when TSPIxCS0/1/2/3 is deasserted after serial transfer completion.
To set a TSPIxCS0/1/2/3 deassert delay time, set
[TSPIxFMTR0]
<SCKCSDL>.
(3) Interval time between frames in the burst transfer
“t
c
” is an interval time between frames in the burst transfer. To set an interval time between frames, set
[TSPIxFMTR0]
<FINT>.
(4) Minimum idle time
“t
d
” is a minimum wait time from the time when TSPIxCS0/1/2/3 is deasserted and then until
TSPIxCS0/1/2/3 is asserted again. To set the minimum idle time, set
[TSPIxFMTR0]
<CSINT>.
Figure 3.20 Transfer format and timing adjustment(Example for 2
nd
edge sampling)
Output level specified by
[
TSPIxCR2]
<TIDLE>.