Appendix E. Processor Core Register Summary
E-13
PowerPC Register Set
•
Miscellaneous registers
— The time base facility (TB) for writing. The TB is a 64-bit register pair that can
be used to provide time of day or interval timing. It consists of two 32-bit
registers—time base upper (TBU) and time base lower (TBL). The TB is
incremented once every four sys_logic_clk cycles.
— Decrementer (DEC). The DEC register is a 32-bit decrementing counter that
provides a mechanism for causing a decrementer exception after a
programmable delay. The DEC is decremented once every four sys_logic_clk
cycles.
— External access register (EAR). This optional register is used in conjunction with
the eciwx and ecowx instructions. While the PowerPC architecture specifies that
the low-order six bits of the EAR (bits 26–31) are used to select a device, the
603e and MPC8240 only implement the low-order 4 bits (bits 28–31). Note that
the EAR register and the eciwx and ecowx instructions are optional in the
PowerPC architecture and may not be supported in all PowerPC processors that
implement the OEA.
E.1.3.1 Machine State Register (MSR)
The machine state register (MSR) is shown in Figure E-10.
Figure E-10. Machine State Register (MSR)
Table E-8 shows the bit definitions for the MSR.
Table E-8. MSR Bit Settings
Bit(s)
Name
Reset
Value
Description
0–12
—
0
Reserved
13
POW
0
Power management enable (603e-specific)
0 Power management disabled (normal operation mode)
1 Power management modes enabled (doze, nap, or sleep mode)
This bit controls the programmable power modes only; it has no effect on dynamic power
management (DPM). MSR[POW] may be altered with an mtmsr instruction only. Also,
when altering the POW bit, software may alter only this bit in the MSR and no others with
the same instruction. The mtmsr instruction must be followed by a context-synchronizing
instruction.
0
12
13
14 15 16 17 18 19 20 21 22 23
24 25 26 27 28 29 30 31
Reserved
0000 0000 0000 0
POW
ILE EE PR FP ME FE0 SE BE FE1 0
IP IR DR 00
RI LE
TGPR
Summary of Contents for MPC8240
Page 1: ...MPC8240UM D Rev 1 1 2001 MPC8240 Integrated Processor User s Manual ...
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Page 48: ...xlviii MPC8240 Integrated Processor User s Manual Acronyms and Abbreviations ...
Page 312: ...6 94 MPC8240 Integrated Processor User s Manual ROM Flash Interface Operation ...
Page 348: ...7 36 MPC8240 Integrated Processor User s Manual PCI Host and Agent Modes ...
Page 372: ...8 24 MPC8240 Integrated Processor User s Manual DMA Register Descriptions ...
Page 394: ...9 22 MPC8240 Integrated Processor User s Manual I2O Interface ...
Page 412: ...10 18 MPC8240 Integrated Processor User s Manual Programming Guidelines ...
Page 454: ...12 14 MPC8240 Integrated Processor User s Manual Internal Arbitration ...
Page 466: ...13 12 MPC8240 Integrated Processor User s Manual Exception Latencies ...
Page 516: ...16 14 Watchpoint Trigger Applications ...
Page 538: ...B 16 MPC8240 Integrated Processor User s Manual Setting the Endian Mode of Operation ...
Page 546: ...C 8 MPC8240 Integrated Processor User s Manual ...
Page 640: ...INDEX Index 16 MPC8240 Integrated Processor User s Manual ...