T
rigger
Set Frq1, ...
Set Frq3, ...
Set Frq2, ...
Set XMOD=3
Set Frq4,...
Set XMOD=2...
2 Pulses
4 Pulses
3 Pulses
5 Pulses
2 Pulses
Frq1
Frq3
Frq2
Frq4
Frq4
High, Low, or Hi-Z
High, Low, or Hi-Z
[Pause]
[Pause]
[E-Pulse]
[E-Pulse]
[S-Pulse]
[X-Pulse]
[X-Pulse]
MT_SW_Pulse
Basic setup of
PPG_A registers
with XMOD=3
ListIndex=0
Trigger PPG_A
wait for XSTAT==2
(E-Pulses)
N
update XPULSE,
XLPER, XHPER
from x-pulse list
wait for XSTAT==3
(X-Pulses)
N
update EPULSE,
LPER, HPER from
e-pulse list
Incr. ListIndex
End of list ?
N
Set XMOD=2
End
Programmable Pulse Generator (PPG or PPG_A) Block
502
SLAU367P – October 2012 – Revised April 2020
Copyright © 2012–2020, Texas Instruments Incorporated
Sequencer for Acquisition, Programmable Pulse Generator, and Physical
Interface (SAPH, SAPH_A)
The PPG_A can be triggered by writing 1 to the SAPH_APPGTRIG.PPGTRIG bit when
SAPH_APGCTL.TRSEL = 0 (register mode) or by the acquisition sequencer (ASQ) when
SAPH_APGCTL.TRSEL = 1 (auto mode). To avoid unintended pulse outputs, keep
SAPH_APGCTL.PPGEN = 0 while preparing the PPG_A registers. After the PPG_A registers are
prepared, write 1 to the SAPH_APGCTL.PPGEN bit before triggering the PPG_A. The
SAPH_APGCTL.PPGEN bit must be set before triggering the PPG_A. The output channel is determined
by the SAPH_APGCTL.PPGCHSEL bit when SAPH_APGCTL.PGSEL = 0 (register mode) or by the
acquisition sequencer (ASQ) when SAPH_APGCTL.PGSEL = 1 (auto mode). Another layer of output
control is inside the PHY, so both blocks must be configured properly (see
). After software
sets XMOD = 2 by directly writing or using the DMA, the PPG_A automatically stops when it completes
generating the pulses. Setting XMOD = 2 must be done when entering the last X-Pulse state. The current
PPG_A state is indicated in SAPH_AXPGCTL.XSTAT Leave at least 6 CPU clocks time margin for
synchronizing. To stop generating pulses before completion, regardless of operation mode, write 1 to
SAPH_APGCTL.STOP. The PPG_A immediately stops generating pulses. The SAPH_APGCTL.STOP bit
is automatically cleared to zero.
Figure 21-10. PPG_A Software Flow Chart for Multi Tone
Figure 21-11. PPG_A Multi Tone Generation With SAPHPGC.PPOL = 1
(Starts With Low Polarity)