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Power Management
9-4
Freescale Semiconductor
9.2.3
Peripheral Power Management Clear Register (PPMCR0)
The PPMCR register provides a simple mechanism to clear a given bit in the PPMHR and PPMLR
registers, enabling the clock for a given peripheral module without needing to perform a read-modify write
on the PPMR. The data value on a register write causes the corresponding bit in the PPM{H,L}R to be
clear. A value of 64 to 127 (setting the CAMCD bit) provides a global clear function, forcing the entire
PPMR contents to clear, enabling all peripheral module clocks. Reads of these registers return all zeroes.
9.2.4
Peripheral Power Management Registers (PPMHR0 and PPMLR0)
The PPMR registers provide a bit map for controlling the generation of the peripheral clocks for each
decoded address space. Recall each peripheral module is mapped into 16 kByte slots within the memory
map. The PPMR registers provide a unique control bit for each address space that defines whether the
module clock for the given space is enabled or disabled.
Because the operation of the crossbar switch and the system control module (SCM) are fundamental to the
operation of the device, the clocks for these modules cannot be disabled.
Table 9-3. PPMSR0 Field Descriptions
Field
Description
7
Reserved, must be cleared.
6
SAMCD
Set all module clock disables.
0 Set only those bits specified in the SMCD field
1 Set all bits in PPMRH and PPMRL, disabling all peripheral clocks
5–0
SMCD
Set module clock disable. Set the corresponding bit in PPM{H,L}R, disabling the peripheral clock.
Address: 0xFC04_002D (PPMCR0)
Access: Supervisor Write-only
7
6
5
4
3
2
1
0
R
0
0
0
0
0
0
0
0
W
CAMCD
CMCD
Reset:
0
0
0
0
0
0
0
0
Figure 9-3. Peripheral Power Management Clear Register (PPMCR0)
Table 9-4. PPMCR0 Field Descriptions
Field
Description
7
Reserved, must be cleared.
6
CAMCD
Clear all module clock disables.
0 Clear only those bits specified in the CMCD field
1 Clear all bits in PPMRH and PPMRL, enabling all peripheral clocks
5–0
CMCD
Clear module clock disable. Clear the corresponding bit in PPMR{H,L}, enabling the peripheral clock.
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 ...