PowerQUICC II Initializations
•Refresh the SDRAM eight times (OP=001)
•Write the SDRAM Mode register (OP=011). For the main SDRAM placed on the 60x bus, the row/column address multiplexing is done externally, so the mode register value must be coded in the column address of the dummy access following the PSDMR programming.
•Reset the xDMR register OP field for normal operation (OP=000).
The refresh periods for the SDRAM devices are defined by one common Memory Refresh Timer Prescaler Register (MPTPR) and by two individual SDRAM Refresh Timer Registers (PSTR for the 60x bus and LSTR for the local bus).
On the 4538, no CPM local memory is present.
GPCM Controller Initialization
The initialization of a GPCM controller is done entirely in the bank Option Register (ORx).
On the 4538, the Flash EEPROM is controlled in bank 0 by a GPCM.
UPM Controller Programming
User Programmable Machine A (UPMA) is used to control accesses to the QuadFALC.
MPC603e Core Initialization
For full description of the MPC603e registers, read Motorola documents: MPC603e a EC606e RISC Microprocessors User’s Manual (ref MPC603EUM/AD) and PowerPC Microprocessor Family: The Programmer’s Reference Guide (ref
MMU Initialization
The 4538 local memory mapping is organized in such a way that the Block Address Translation (BAT) mechanism can be used rather than the more complicated Segments and Translation
In the Boot Firmware, the MMU is initialized using the BAT mechanism. The cachable areas are defined in the BAT blocks. Once the IBATx and DBATx special purpose registers initialized, Address Translation is enabled for instruction and data in the Machine State Register (MSR).
Cache Initialization
The data and instruction caches are automatically invalidated after a
66 | Interphase Corporation |