Acquisition Sequencer (ASQ)
513
SLAU367P – October 2012 – Revised April 2020
Copyright © 2012–2020, Texas Instruments Incorporated
Sequencer for Acquisition, Programmable Pulse Generator, and Physical
Interface (SAPH, SAPH_A)
21.4.4 Auto Mode and Register Mode
The entire measurement sequence can be controlled by user software (called register mode) or by the ASQ without any CPU intervention (called
auto mode). See
for differences. Configuration of each submodule is the same and is not listed in
Table 21-4. Auto Mode and Register Mode
Action
Auto Mode
Control Register in Auto Mode
Register Mode
Control Register in Register
Mode
Take USS submodules out of reset
(once after reset)
UUPSCTL.SWRST = 0
UUPSCTL.SWRST
UUPSCTL.SWRST = 0
UUPSCTL.SWRST
Enable auto mode or register mode
(on mode changes)
SAPHMCNF.LPBE = 0
SAPHMCNF.LPBE
SAPHMCNF.LPBE = 0
SAPHMCNF.LPBE
Set TxBias and RxBias impdance
SAPHMCNF.BIMP = 0, 1, 2, 3
SAPHMCNF.BIMP
SAPHMCNF.BIMP = 0, 1, 2, 3
SAPHMCNF.BIMP
Drive output drivers to GND
SAPHOSEL.PCH0SEL = 1
N/A (automatic)
SAPHOSEL.PCH0SEL = 0
SAPHOCTL0.CH0TERM,
SAPHOCTL0.CH1TERM
Tx bias
SAPHBCTL.ASQBSW = 1
N/A (automatic)
SAPHBCTL.ASQBSW = 0
SAPHBCTL.CH0EBSW,
SAPHBCTL.CH1EBSW
Select output channel in PPG
SAPHPGCTL.PGSEL = 1
SAPHASCTL0.ASQCHSEL,
SAPHASCTL1.CHTOG
SAPHPGCTL.PGSEL = 0
SAPHPGCTL.PPGCHSEL
Trigger PPG
SAPHPGCTL.TRSEL = 1
SAPHATM_A
SAPHPGCTL.TRSEL = 0
SAPHPPGTRIG.PPGTRIG
Input channel selection
SAPHICTL0.MUXCTL = 1
SAPHASCTL0.ASQCHSEL,
SAPHASCTL1.CHTOG,
SAPHASCTL1.CHOWN
SAPHICTL0.MUXCTL = 0
SAPHICTL0.MUXSEL
Turn on the SDHS
SDHSCTL0.TRGSRC = 1
SAPHATM_B
SDHSCTL0.TRGSRC = 0
SDHSCTL4.SDHSON
Rx bias
SAPHBCTL.ASQBSW = 1
SAPHATM_C or
SAPHASCTL1.EARLYRB
SAPHBCTL.ASQBSW = 0
SAPHBCTL.PGABSW,
SAPHICTL0.MUXSEL
SDHS conversion start
SDHSCTL0.TRGSRC = 1
SAPHATM_D
SDHSCTL0.TRGSRC = 0
SDHSCTL5.SSTART
The number of measurement
Triggering ASQ
SAPHASCTL0.PNGCNT (up to 4)
No ASQ trigger
N/A
The order of the time mark events is determined by the counter values written to the SAPHATM_x registers.