Peripheral Halt Control
316
SLAU356I – March 2015 – Revised June 2019
Copyright © 2015–2019, Texas Instruments Incorporated
System Controller A (SYSCTL_A)
5.5
Peripheral Halt Control
The Peripheral Halt Control (SYS_PERIHALT_CTL) register in the SYSCTL_A module allows the user
independent control over the functionality of device peripherals during code development and debug.
When the CPU is halted, the bits in this register can control whether the corresponding peripheral freezes
its operation (such as incrementing, transmit, and receive) or continues its operation (debug remains
nonintrusive). The registers of the peripheral remain accessible regardless of the value in the
SYS_PERIHALT_CTL register.
5.6
Glitch Filtering on Digital I/Os
Some of the interrupt- and wakeup-capable digital I/Os can suppress glitches through the use of an
analog glitch filter to prevent unintentional interrupt or wakeup during device operation. The analog filter
suppresses a minimum of 250-ns wide glitches. The glitch filter on these selected digital I/Os is enabled
by default. If glitch filtering is not required in the application, it can be disabled using the
SYS_DIO_GLTFLT_CTL register. When the GLTFLT_EN bit in this register is cleared, the glitch filters on
all the digital I/Os are bypassed. The glitch filter is automatically bypassed on a digital I/O when it is
configured for peripheral or analog functionality by programming the respective PySEL0.x and PySEL1.x
registers.
5.7
Reset Status and Override Control
The SYSCTL_A module includes registers to monitor the status of the various classes of resets in the
device. In addition, SYSCTL_A can override the device resets and initiate reset requests for debug
purposes. See
for details.
NOTE:
Reset overrides are for debug of application code and can take effect only when the debug
security is inactive.
5.8
Device Security
This section describes the device security options and how to configure device security on devices in the
MSP432P4xx device family.
5.8.1 Device Security Introduction
One of the most important functions of the SYSCTL_A module is the security control of the device. The
SYSCTL_A can secure the device against accesses from the debugger (JTAG and SWD lock feature). In
addition, the SYSCTL_A enables security control for different configurable zones of the device (IP
protection feature). The application can load a secure code (IP software or middleware) into the device
flash memory and configure that zone of memory as secure. This section deals with how the application
can set up the device for the various device security options.
5.8.2 Device Security Components
The SYSCTL_A module achieves device security by interacting with the following components on the
device.
•
Device boot code
•
Flash JTAG mailbox mechanism for application-level interaction with device boot code
5.8.3 JTAG and SWD Lock Based Security
Debugger access to the device through JTAG or SWD can be blocked during the boot process. However,
the JTAG and SWD interface can still access certain SYSCTL_A registers in the device. The application
must initiate a boot override in the system to enable JTAG and SWD lock. See
for details on
boot overrides.
Access into a completely locked device can be enabled again by a factory reset boot override request
through the SYSCTL_A registers and the flash boot-override mailbox.