MPC5xxx中的主题 Re: Flash Usage - Block Type

Flash Usage - Block Type

wayneyounghoney — Tue, 16 Oct 2018 20:04:55 GMT

I have some questions on the Flash system:

Is there any significance or meaning to the Block Type attribute (Low/Mid/High/Large)? Is it some convention indicating where they are located in the memory map, although "High" doesn't seem to be in the high area and "Large" doesn't seem to fit the other terms.

Can someone confirm that you can execute code from the lower flash areas (RWW 0,1,2,3,4,5):

Start address	End address	Allocated size (KB)	RWW partition	Block number	Block type	Example use
0x00000000	0x0000FFFF	64	0	0	Low	EEPROM data
0x00010000	0x0001FFFF	64	1	1	Low	EEPROM data
0x00020000	0x0002FFFF	64	2	0	Mid	EEPROM data
0x00030000	0x0003FFFF	64	3	1	Mid	EEPROM data
0x00040000	0x003FFFFF	3840	—	—	Not available	n/a
0x00400000	0x00403FFF	16	0	0	UTEST	See Table 4-3
0x00404000	0x005FFFFF	2032	—	—	Not available	n/a
0x00600000	0x00603FFF	16	4	0	High	CSE
0x00604000	0x00607FFF	16	5	1	High	CSE

Why do RWWs 0,2 have a Block 0 but RWWs 1, 3 have a Block 1 (and not a Block 0)? Any significance to this?
If you do not use the CSE can the RWW 4 and 5 be used for any code or data use?
The total available Flash is 8480KB (8192KB of Large and 288KB of Low/Mid/High)

Re: Flash Usage - Block Type

davidtosenovjan — Wed, 17 Oct 2018 13:48:24 GMT

Could you specify used device?

Re: Flash Usage - Block Type

wayneyounghoney — Wed, 17 Oct 2018 13:51:13 GMT

The MPC5777C.

Re: Flash Usage - Block Type

davidtosenovjan — Wed, 17 Oct 2018 15:34:44 GMT

The block type affects mainly endurance and data retention as you can see below (datasheet screenshot):

You can execute code from the lower flash areas, but areas with higher endurance (smaller block) are mainly intended for EEPROM emulation, but you can execute code from these area as well. I am not completely sure about CSE blocks, I am finding it out, returning to you.

Regarding blocks and partitions, blocks are numbered in ascending order withing one block type, partitions the same way withing the whole flash. Just matter of implementation.

Re: Flash Usage - Block Type

davidtosenovjan — Thu, 18 Oct 2018 13:00:58 GMT

CSE flash blocks cannot be used for general purpose functionality because of reason below:

Re: Flash Usage - Block Type

wayneyounghoney — Wed, 07 Nov 2018 14:48:44 GMT

Hi David. Thanks for the info. I appreciate it.