Texas Instruments TMS320 2833 Series User Manual

For MEP range and rounding adjustment (0x0180 in Q8 format)
[
+1.5
]
Operational Description of HRPWM www.ti.com
328
SPRUI07–March 2020
Submit Documentation Feedback
Copyright © 2020, Texas Instruments Incorporated
High-Resolution Pulse Width Modulator (HRPWM)
4.2 Operational Description of HRPWM
The HRPWM is based on micro edge positioner (MEP) technology. MEP logic is capable of positioning an
edge very finely by sub-dividing one coarse system clock of a conventional PWM generator. The time step
accuracy is on the order of 150 ps. See the device-specific data sheet for the typical MEP step size on a
particular device. The HRPWM also has a self-check software diagnostics mode to check if the MEP logic
is running optimally, under all operating conditions. Details on software diagnostics and functions are in
Section 4.2.4.
Figure 4-2 shows the relationship between one coarse system clock and edge position in terms of MEP
steps, which are controlled via an 8-bit field in the Compare A extension register (CMPAHR).
Figure 4-2. Operating Logic Using MEP
To generate an HRPWM waveform, configure the TBM, CCM, and AQM registers as you would to
generate a conventional PWM of a given frequency and polarity. The HRPWM works together with the
TBM, CCM, and AQM registers to extend edge resolution, and should be configured accordingly. Although
many programming combinations are possible, only a few are needed and practical. These methods are
described in Section 4.2.5.
Registers discussed but not found in this chapter can be found in the Enhanced Pulse Width Modulator
(ePWM) chapter.
The HRPWM operation is controlled and monitored using the following registers:
(1)
This register is EALLOW protected.
Table 4-2. HRPWM Registers
mnemonic Address Offset Shadowed Description
TBPHSHR 0x0002 No Extension Register for HRPWM Phase (8 bits)
CMPAHR 0x0008 Yes Extension Register for HRPWM Duty (8 bits)
HRCNFG
(1)
0x0020 No HRPWM Configuration Register
4.2.1 Controlling the HRPWM Capabilities
The MEP of the HRPWM is controlled by two extension registers, each 8-bits wide. These two HRPWM
registers are concatenated with the 16-bit TBPHS and CMPA registers used to control PWM operation.
• TBPHSHR - Time Base Phase High Resolution Register
• CMPAHR - Counter Compare A High Resolution Register

Texas Instruments TMS320 2833 Series Specifications

General

Brand	Texas Instruments
Model	TMS320 2833 Series
Category	Controller
Language	English