Motorola PrPMC800/800ET Processor PMC Module Manual De Usuario
5 PPCBug
PrPMC800/800ET Processor PMC Module Installation and Use (PrPMC800A/IH5)
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Physically, PPCBug is contained in two on-board flash devices that together provide 32MB of
storage. The executable code is checksummed at every power-on or reset firmware entry, and
the result (which includes a precalculated checksum contained in the flash devices), is verified
against the expected checksum.
storage. The executable code is checksummed at every power-on or reset firmware entry, and
the result (which includes a precalculated checksum contained in the flash devices), is verified
against the expected checksum.
MPU, Hardware, and Firmware Initialization
The debugger performs the MPU, hardware, and firmware initialization process. This process
occurs each time the PrPMC800/800ET is reset or powered up. The steps below are a high-
level outline; not all of the detailed steps are listed.
occurs each time the PrPMC800/800ET is reset or powered up. The steps below are a high-
level outline; not all of the detailed steps are listed.
1. Sets MPU.MSR to known value.
2.
Invalidates the MPU’s data/instruction caches.
3.
Clears all segment registers of the MPU.
4.
Clears all block address translation registers of the MPU.
5.
Initializes the MPU-bus-to-PCI-bus bridge device.
6.
Calculates the external bus clock speed of the MPU.
7.
Delays for 750 milliseconds.
8.
Determines the CPU base board type.
9.
Sizes the local read/write memory (i.e., DRAM).
10. Initializes the read/write memory controller. Sets base address of memory to
$00000000.
11. Retrieves the speed of read/write memory.
12. Initializes the read/write memory controller with the speed of read/write memory.
13. Retrieves the speed of read only memory (flash).
14. Initializes the read only memory controller with the speed of read only memory.
15. Enables the MPU’s instruction cache.
16. Copies the MPU’s exception vector table from $FFF00000 to $00000000.
17. Verifies MPU type.
18. Enables the superscalar feature of the MPU (superscalar processor boards only).
19. Verifies the external bus clock speed of the MPU.
20. Determines the debugger’s console/host ports, and initializes the PC16550A.
21. Displays the debugger’s copyright message.
22. Displays any hardware initialization errors that may have occurred.
23. Checksums the debugger object, and displays a warning message if the checksum
failed to verify.
24. Displays the amount of local read/write memory found.