System Control Registers
207
SPRUH22I – April 2012 – Revised November 2019
Copyright © 2012–2019, Texas Instruments Incorporated
System Control and Interrupts
1.13.5.12 C28 NMI Watchdog Period (CNMIWDPRD) Register
Figure 1-69. C28 NMI Watchdog Period (CNMIWDPRD) Register
15
0
NMIWDPRD
R/W-0xFFFF
LEGEND: R/W = Read/Write; R = Read only; -
n
= value after reset
Table 1-80. C28 NMI Watchdog Period (CNMIWDPRD) Register Field Descriptions
Bit
Field
Value
Description
15-0
NMIWDPRD
NMI Watchdog Period
This 16-bit value contains the period value at which a reset is generated when the watchdog
counter matches. At reset this value is set at the maximum. The software can decrease the period
value at initialization time.
Writing a PERIOD value that is smaller then the current counter value will automatically force an
NMIRS to the C28 and hence reset the watchdog counter.
1.13.5.13 PIE Interrupt Registers
1.13.5.13.1 PIE, Control (PIECTRL) Register
Figure 1-70. PIE, Control (PIECTRL) Register
15
1
0
PIEVECT
ENPIE
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -
n
= value after reset
Table 1-81. PIE, Control (PIECTRL) Register Field Descriptions
Bits
Field
Value
Description
15-1
PIEVECT
These bits indicate the address within the PIE vector table from which the vector was fetched. The
least significant bit of the address is ignored and only bits 1 to 15 of the address is shown. You can
read the vector value to determine which interrupt generated the vector fetch.
For Example:
If PIECTRL = 0x0D27 then the vector from address 0x0D26 (illegal operation) was
fetched.
0
ENPIE
Enable vector fetching from PIE vector table.
Note:
The reset vector is never fetched from the PIE, even when it is enabled. This vector is always
fetched from boot ROM.
0
If this bit is set to 0, the PIE block is disabled and vectors are fetched from the CPU vector table in
boot ROM. All PIE block registers (PIEACK, PIEIFR, PIEIER) can be accessed even when the PIE
block is disabled.
1
When ENPIE is set to 1, all vectors, except for reset, are fetched from the PIE vector table. The
reset vector is always fetched from the boot ROM.
1.13.5.13.2 PIE, Acknowledge (PIEACK) Register
Figure 1-71. PIE, Acknowledge (PIEACK) Register
15
12
11
0
Reserved
PIEACK
R-0
R/W1C-1
LEGEND: R/W1C = Read/Write 1 to clear; R = Read only; -
n
= value after reset