Hello all,
I have to program the internal flash (it is called UC3F) of an MPC563 PowerPC. After having read the Reference Manual's chapter three times, I still don't understand fully how to write a sequence of bytes to the flash. I am sure that it is not that difficult, but it's the first time I have this kind of task.
From what I understand:
In order to rewrite the flash, you must first erase it.
Writing the Flash is done via a Hardware State Machine.
I have found this code snippets in
#define C3F_ADDR 0x002FC800 // C3F register base address #define UC3F_A (*((volatile unsigned long *)(0x00000000))) // flash memory location
.... C3F[0] = (struct C3F_tag *)(C3F_ADDR);
//erase C3F[0]->C3FMCR.PROTECT = 0; //Disable Protect C3F[0]->C3FCTL.PE = 1; C3F[0]->C3FCTL.SES = 1; UC3F_A = 0xffffffff; //garbage value C3F[0]->C3FCTL.EHV = 1; while( C3F[0]->C3FCTL.HVS != 0 ); while(C3F[0]->C3FCTL.PEGOOD != 1);
C3F[0]->C3FCTL.EHV = 0; C3F[0]->C3FCTL.SES = 0;
//write C3F[0]->C3FMCR.PROTECT = 0; C3F[0]->C3FCTL.SES = 1; C3F[0]->C3FCTL.PE = 0; UC3F_A = 0xCCCCCCCC; C3F[0]->C3FCTL.EHV = 1; while( C3F[0]->C3FCTL.HVS != 0 );
while(C3F[0]->C3FCTL.PEGOOD != 1);
C3F[0]->C3FCTL.EHV = 0; C3F[0]->C3FCTL.SES = 0;
I understand the 'frame' of the erase and write blocks: First the registers are set to initiate the erase/write process, then comes the 'interesting' middle part. Finally, you have to poll for two status bits and reset two initiating bits.
But I don't understand this middle part. How do I determine the flash address to be written to, and how do I determine the content (byte, int, long or whatever) to write to that address? In the code above, UC3F_A is the first memory location of the flash. Does this mean that
UC3F_A = 0xCCCCCCCC;
writes 0xCCCCCCCC to this memory location?
The processor manual implies to me that the first write determines the address and the second determines the data, but I probably don't understand it:
"Programming write ? A successful write to the array location to be programmed. This write updates the program data latch with the information to be programmed. In addition, the addressof the first programming write is latched in the UC3F memory interface block. All accesses of the array after the first write are to the same address regardless of the address provided. Thus the locations accessed after the first programming write are limited to the location to be programmed."
Anyway, the code above only writes to one flash memory location. Does this mean, I have to repeat the whole sequence to write to the next location?
Any help would be great.
Best regards
Johannes