Programmable Interrupt Timers (PIT0–PIT3)
29-2
Freescale Semiconductor
NOTE
The low-power interrupt control register (LPICR) in the system control
module specifies the interrupt level at or above which the device can be
brought out of a low-power mode.
In wait mode, the PIT module continues to operate as in run mode and can be configured to exit the
low-power mode by generating an interrupt request. In doze mode with the PCSR
n
[DOZE] bit set, PIT
module operation stops. In doze mode with the PCSR
n
[DOZE] bit cleared, doze mode does not affect PIT
operation. When doze mode is exited, PIT continues operating in the state it was in prior to doze mode. In
stop mode, the internal bus clock is absent and PIT module operation stops.
In debug mode with the PCSR
n
[DBG] bit set, PIT module operation stops. In debug mode with the
PCSR
n
[DBG] bit cleared, debug mode does not affect PIT operation. When debug mode is exited, the PIT
continues to operate in its pre-debug mode state, but any updates made in debug mode remain.
29.2
Memory Map/Register Definition
This section contains a memory map (see
) and describes the register structure for PIT0–PIT3.
NOTE
Longword accesses to any of the programmable interrupt timer registers
results in a bus error. Only byte and word accesses are allowed.
Table 29-1. PIT Module Operation in Low-power Modes
Low-power Mode
PIT Operation
Mode Exit
Wait
Normal
N/A
Doze
Normal if PCSR
n
[DOZE] cleared,
stopped otherwise
Any interrupt at or above level in LPICR, exit doze
mode if PCSR
n
[DOZE] is set. Otherwise
interrupt assertion has no effect.
Stop
Stopped
No
Debug
Normal if PCSR
n
[DBG] cleared,
stopped otherwise
No. Any interrupt is serviced upon normal exit
from debug mode
Table 29-2. Programmable Interrupt Timer Modules Memory Map
Address
Register
Width
(bits)
Access
1
Reset Value
Section/Page
PIT 0
PIT 1
PIT 2
PIT 3
Supervisor Access Only Registers
2
0xFC08_0000
0xFC08_4000
0xFC08_8000
0xFC08_C000
PIT Control and Status Register (PCSR
n
)
16
R/W
0x0000
Summary of Contents for MCF54455
Page 33: ...xxviii Freescale Semiconductor ...
Page 67: ...Freescale Semiconductor 1 ...
Page 125: ...Freescale Semiconductor 1 ...
Page 145: ...Enhanced Multiply Accumulate Unit EMAC 5 21 Freescale Semiconductor ...
Page 173: ...Cache 6 28 Freescale Semiconductor ...
Page 179: ...Static RAM SRAM 7 6 Freescale Semiconductor ...
Page 207: ...Power Management 9 16 Freescale Semiconductor ...
Page 323: ...Reset Controller Module 13 8 Freescale Semiconductor ...
Page 389: ...Pin Multiplexing and Control 16 44 Freescale Semiconductor ...
Page 575: ...PCI Bus Controller 22 58 Freescale Semiconductor ...
Page 600: ...Advanced Technology Attachment ATA Freescale Semiconductor 23 25 ...
Page 601: ...Freescale Semiconductor 1 ...
Page 842: ...I2 C Interface Freescale Semiconductor 33 16 ...
Page 843: ...Freescale Semiconductor 1 ...
Page 921: ...Revision History A 6 Freescale Semiconductor ...