MSC8144E Reference Manual, Rev. 3
5-2
Freescale
Semiconductor
Reset
5.1.1 Reset Sources
Table 5-1 describes reset sources.
5.1.2 Reset Actions
The MSC8144E reset control logic determines the cause of reset, synchronizes it if necessary,
and resets the appropriate internal hardware. Each reset flow has different impact on the device
logic. Power-on reset has the greatest impact, resetting the entire device, including clock logic
and error capture registers. Hard reset resets the entire device excluding clock logic and error
capture registers, while Soft reset initializes the internal logic while maintaining the system
configuration. All reset types generate a reset to the cores. The memory controllers, system
protection logic, interrupt controller, and I/O pins are initialized only on hard reset. Soft reset
initializes the internal logic while maintaining the system configuration. Asserting external
SRESET
generates a soft reset to the DSP cores and to the remainder of the device. Table 5-2
identifies reset actions for each reset source.
Table 5-1. Reset Sources
Name Description
Power-on reset (PORESET)
Input pin. Asserting this pin initiates the power-on reset flow that resets all the device and
configures various attributes of the device including its clock modes.
Hard reset (HRESET)
This is a bidirectional I/O pin. The MSC8144E can detect an external assertion of
HRESET only if it occurs while the MSC8144E is not asserting reset. During HRESET,
SRESET is asserted. HRESET is an open-drain pin.
Soft reset (SRESET)
Bidirectional I/O pin. The MSC8144E can only detect an external assertion of SRESET if
it occurs while the MSC8144E is not asserting reset. SRESET is an open-drain pin.
Software watchdog reset
After the MSC8144E watchdog timer counts to zero, a software watchdog reset is
generated. The enabled software watchdog event then generates an internal hard reset
sequence.
RapidIO reset
When the RapidIO logic asserts the RapidIO hard reset signal, an internal hard reset
sequence is generated.
JTAG reset
When JTAG logic asserts the JTAG soft reset signal, an internal soft reset sequence is
generated.
Software hard reset
A hard reset sequence can be initialized by writing to a memory mapped register (RCR)
Software soft reset
A soft reset sequence can be initialized by writing to a memory mapped register (RCR)
Summary of Contents for MSC8144E
Page 1: ...MSC8144E Reference Manual Quad Core Media Signal Processor MSC8144ERM Rev 3 July 2009 ...
Page 48: ...MSC8144E Reference Manual Rev 3 xlviii Freescale Semiconductor ...
Page 86: ...MSC8144E Reference Manual Rev 3 1 38 Freescale Semiconductor Overview ...
Page 168: ...MSC8144E Reference Manual Rev 3 3 60 Freescale Semiconductor External Signals ...
Page 242: ...MSC8144E Reference Manual Rev 3 5 26 Freescale Semiconductor Reset ...
Page 314: ...MSC8144E Reference Manual Rev 3 8 24 Freescale Semiconductor General Configuration Registers ...
Page 414: ...MSC8144E Reference Manual Rev 3 10 14 Freescale Semiconductor MSC8144E SC3400 DSP Subsystem ...
Page 452: ...MSC8144E Reference Manual Rev 3 11 38 Freescale Semiconductor Internal Memory Subsystem ...
Page 520: ...MSC8144E Reference Manual Rev 3 12 68 Freescale Semiconductor DDR SDRAM Memory Controller ...
Page 1070: ...MSC8144E Reference Manual Rev 3 21 28 Freescale Semiconductor Timers ...