00
01
10
11
SAPHOSEL.PCH0SEL
SAPHOCTL0.
CH0OE
SAPHOCTL0.
CH0OUT
SAPHOCTL0.
CH0TERM
From ASQ
(No software control)
00
01
10
11
00
01
10
11
From ASQ
(No
control)
software
CH0OUT
From PPG
SAPHOCTL1.
CH0FP
Enable
CH0_OUT (Pin)
00
01
10
11
SAPHOSEL.PCH1SEL
SAPHOCTL0.
CH1OE
SAPHOCTL0.
CH1OUT
SAPHOCTL0.
CH0TERM
From ASQ
(No
control)
software
00
01
10
11
00
01
10
11
From ASQ
(No
control)
software
CH0OUT
From PPG
SAPHOCTL1.
CH1FP
Enable
CH1_OUT (Pin)
SWG1
DRV1
SWG0
DRV0
Physical Interface (PHY) Block
504
SLAU367P – October 2012 – Revised April 2020
Copyright © 2012–2020, Texas Instruments Incorporated
Sequencer for Acquisition, Programmable Pulse Generator, and Physical
Interface (SAPH, SAPH_A)
21.3 Physical Interface (PHY) Block
The PHY controls the input and output pins of the USS module. The USS module has dedicated pins
(CH0_OUT, CH0_IN, CH1_OUT, CH1_IN, two PVSS, and PVCC), which are controlled by the USS
module, not by the digital I/O module.
21.3.1 Output Channels (CH0_OUT and CH1_OUT)
shows the functional block diagram for the output channels, CH0_OUT and CH1_OUT.
Figure 21-12. PHY Output Pins
The output pins (CH0_OUT and CH1_OUT) can be used as general I/O pins when
SAPHOSEL.PCH0SEL = 0 or 3. In this case, the polarity of the two pins is controlled by
SAPHOCTL0.CH0OUT and SAPHOCTL0.CH1OUT, and the pins are enabled or disabled (Hi-Z) by
SAPHOCTL0.CH0OE and SAPHOCTL0.CH1OE. The pins can be connected to GND through the SWG0
and SWG1 switches by SAPHOCTL0.CH0TERM and SAPHOCTL0.CH1TERM, respectively.
When SAPHOSEL.PCH0SEL = 1, the output pins work as single output drivers. The pulses generated by
PPG are output on the selected pin. This is the typical use case for the flow measurement application.