Programmable Pulse Generator (PPG or PPG_A) Block
503
SLAU367P – October 2012 – Revised April 2020
Copyright © 2012–2020, Texas Instruments Incorporated
Sequencer for Acquisition, Programmable Pulse Generator, and Physical
Interface (SAPH, SAPH_A)
21.2.6 Excitation Pulse Frequency on PPG or PPG_A
The excitation pulse frequency is determined by the PPG clock frequency and the SAPHPGLPER.LPER
and SAPHPGHPER.HPER bits. The high duration of a regular excitation pulse and low duration of a
regular excitation pulse are determined by SAPHPGHPER.HPER (8 bits) and SAPHPGLPER.LPER
(8 bits), respectively. Thus:
•
Excitation pulse frequency = HSPLL frequency / ( SAPHPGHPER.HPER + SAPHPGLPER.LPER)
21.2.7 Extra Excitation Pulse Frequency on PPG_A
The pulse frequency for the X-Pulses is determined by the PPG_A clock frequency and the
SAPH_AXPGLPER.XLPER and SAPH_AXPGHPER.XHPER bits. The high duration of an extra excitation
pulse and low duration of an extra excitation pulse are determined by SAPH_AXPGHPER.XHPER (8 bits)
and SAPH_AXPGLPER.XLPER (8 bits), respectively. Thus:
•
X-Pulse frequency = HSPLL frequency / ( SAPH_AXPGHPER.XHPER + SAPH_AXPGLPER.XLPER)
21.2.8 Test Tone Generation
To start the PPG test tone generation, write SAPHPGCTL.TONE = 1. While SAPHPGCTL.TONE = 1, the
PPG consistently generates excitation pulses (no stop pulse). In this case, SAPHPGC.EPULSE and
SAPHPCG.SPULSE are ignored. To terminate the PPG test tone generation, write
SAPHPGCTL.TONE = 0.