Trip-Zone Submodule Registers - Texas Instruments Concerto F28M35 Series Technical Reference Manual

ePWM Submodules
7.2.7.2 Controlling and Monitoring the Trip-Zone Submodule
The trip-zone submodule operation is controlled and monitored through the following registers:
Register Name
TZSEL
TZDCSEL
TZCTL
TZEINT
TZFLG
TZCLR
TZFRC
TZCLRM
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All trip-zone registers are EALLOW protected and can be modified only after executing the EALLOW instruction. For more
information, see the System Control and Interrupts Reference Guide.
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This register is discussed in more detail in
7.2.7.3 Operational Highlights for the Trip-Zone Submodule
The following sections describe the operational highlights and configuration options for the trip-zone
submodule.
The trip-zone signals TZ1 to TZ6 (also collectively referred to as TZn) are active low input signals. When
one of these signals goes low, or when a DCAEVT1/2 or DCBEVT1/2 force happens based on the
TZDCSEL register event selection, it indicates that a trip event has occurred. Each ePWM module can be
individually configured to ignore or use each of the trip-zone signals or DC events. Which trip-zone signals
or DC events are used by a particular ePWM module is determined by the TZSEL register for that specific
ePWM module. The trip-zone signals may or may not be synchronized to the system clock (SYSCLKOUT)
and digitally filtered within the GPIO MUX block. A minimum of 3*TBCLK low pulse width on TZn inputs is
sufficient to trigger a fault condition on the ePWM module. If the pulse width is less than this, the trip
condition may not be latched by CBC or OST latches. The asynchronous trip makes sure that if clocks are
missing for any reason, the outputs can still be tripped by a valid event present on TZn inputs . The
GPIOs or peripherals must be appropriately configured. For more information, see the device-specific
version of the System Control and Interrupts Reference Guide.
Each TZn input can be individually configured to provide either a cycle-by-cycle or one-shot trip event for
an ePWM module. DCAEVT1 and DCBEVT1 events can be configured to directly trip an ePWM module or
provide a one-shot trip event to the module. Likewise, DCAEVT2 and DCBEVT2 events can also be
configured to directly trip an ePWM module or provide a cycle-by-cycle trip event to the module. This
configuration is determined by the TZSEL[DCAEVT1/2], TZSEL[DCBEVT1/2], TZSEL[CBCn], and
TZSEL[OSHTn] control bits (where n corresponds to the trip input) respectively.
• Cycle-by-Cycle (CBC):
When a cycle-by-cycle trip event occurs, the action specified in the TZCTL[TZA] and TZCTL[TZB] bits
is carried out immediately on the EPWMxA and/or EPWMxB output.
actions. In addition, the cycle-by-cycle trip event flag (TZFLG[CBC]) is set and a EPWMx_TZINT
interrupt is generated if it is enabled in the TZEINT register and PIE peripheral.
If the CBC interrupt is enabled via the TZEINT register, and DCAEVT2 or DCBEVT2 are selected as
CBC trip sources via the TZSEL register, it is not necessary to also enable the DCAEVT2 or DCBEVT2
interrupts in the TZEINT register, as the DC events trigger interrupts through the CBC mechanism.
The specified condition on the inputs is automatically cleared based on the selection made with
TZCLR[CBCPULSE] if the trip event is no longer present. Therefore, in this mode, the trip event is
cleared or reset every PWM cycle. The TZFLG[CBC] flag bit will remain set until it is manually cleared
by writing to the TZCLR[CBC] bit. If the cycle-by-cycle trip event is still present when the TZFLG[CBC]
bit is cleared, then it will again be immediately set.
• One-Shot (OSHT):
When a one-shot trip event occurs, the action specified in the TZCTL[TZA] and TZCTL[TZB] bits is
688
C28 Enhanced Pulse Width Modulator (ePWM) Module
Table 7-20. Trip-Zone Submodule Registers
Address Offset Shadowed
0x12 No
0x13 No
0x14 No
0x15 No
0x16 No
0x17 No
0x18 No
0x71 No
Section 7.2.9, Digital Compare (DC) Submodule.
Copyright © 2012–2019, Texas Instruments Incorporated
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Description
Trip-Zone Select Register
Trip-Zone Digital Compare Select Register
Trip-Zone Control Register
Trip-Zone Enable Interrupt Register
Trip-Zone Flag Register
Trip-Zone Clear Register
Trip-Zone Force Register
Trip-Zone Clear Register Mirror
Table 7-21 lists the possible
SPRUH22I – April 2012 – Revised November 2019
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