Reset Controller Module
MCF52110 ColdFire® Integrated Microcontroller Reference Manual, Rev. 1
Freescale Semiconductor
10-5
Preliminary
10.6
Functional Description
10.6.1
Reset Sources
defines the sources of reset and the signals driven by the reset controller.
To protect data integrity, a synchronous reset source is not acted upon by the reset control logic until the
end of the current bus cycle. Reset is then asserted on the next rising edge of the system clock after the
cycle is terminated. When the reset control logic must synchronize reset to the end of the bus cycle, the
internal bus monitor is automatically enabled regardless of the BME bit state in the chip configuration
register (CCR). Then, if the current bus cycle is not terminated normally, the bus monitor terminates the
cycle based on the length of time programmed in the BMT field of the CCR.
5
SOFT
Software reset flag. Indicates that the last reset was caused by software.
1 Last reset caused by software
0 Last reset not caused by software
4
Reserved, should be cleared.
3
POR
Power-on reset flag. Indicates that the last reset was caused by a power-on reset.
1 Last reset caused by power-on reset
0 Last reset not caused by power-on reset
2
EXT
External reset flag. Indicates that the last reset was caused by an external device asserting the external RSTI pin.
1 Last reset state caused by external reset
0 Last reset not caused by external reset
1
LOC
Loss-of-clock reset flag. Indicates that the last reset state was caused by a PLL loss of clock.
1 Last reset caused by loss of clock
0 Last reset not caused by loss of clock
0
LOL
Loss-of-lock reset flag. Indicates that the last reset state was caused by a PLL loss of lock.
1 Last reset caused by a loss of lock
0 Last reset not caused by loss of lock
Table 10-5. Reset Source Summary
Source
Type
Power on
Asynchronous
External RSTI pin (not stop mode)
Synchronous
External RSTI pin (during stop mode)
Asynchronous
Loss-of-clock
Asynchronous
Loss-of-lock
Asynchronous
Software
Synchronous
LVD reset
Asynchronous
Table 10-4. RSR Field Descriptions (continued)
Field
Description