I am programming ADSP BF514 processor.
Suddenly I wrote the Software Status register of the SPI flash memory to 0x98.
So now BPL=1 and I can write nothing to the BF512's SPI flash memory.
How I can refer page # 809 on the below Hardware reference manual: ADSP-BF51x_hwr_rev1.2.pdf
Executing the write-status-register instruction is ignored when the BPL bit
is set to ‘1’. The BPL bit can only be set from ‘0’ to ‘1’ to lock-down the
status register, but cannot be reset from ‘1’ to ‘0’.
I read the Software Status register after "Power ON" and see state=0x98, (i.e. BPL=1).
What do I need to write BPL= 0?
How I can refer page #790 on the Hardware reference manual: ADSP-BF51x_hwr_rev1.2.pdf
" When BPL is set to ‘1’, it prevents any further alteration of the BPL, BP1,
and BP0 bits. After power-up, the BPL bit is reset to ‘0’. "
I can remove all the power to the board and repower it again.
Before Power_ON I put ADSP BF514 into "Boot from UART0 host" (BMODE2:1:0 = 111).
Then I load to DSP a little firmware to read the Status Register.
I read the Software Status register after "Power ON" and see the state=0x98, (i.e. BPL=1).
Something wrong in this order of the events?
Attempting to write the Software Status register meet with failure!
Another attempt: I put my BF514 undo IZ-ICE and load a little firmware through JTAG.
I read again the Software Status register after "Power ON" and see again the state=0x98, (i.e. BPL=1).
Also I can refer page # 790 on the Hardware reference manual: ADSP-BF51x_hwr_rev1.2.pdf
Block-Protection (BP2, BP1, BP0)
"... The write-status-register (WRSR) instruction is used to program the BP1 and BP0 bits as long as _WP is high or the block-protect-lock (BPL) bit is ‘0’. ..."
So: _WP-pin should unblock SPI flash memory write protection...
Information in Support case: https://ez.analog.com/message/130171#130171
mentioned _WP signal only once:
" I have done the reset to those write protection block bits. Plus WP# is all time high during program, which is set to allow execute WRSR. Looks like it should unblock write protection. "
It seems that _WP = is the signal I am looking for.
Please help me: where can I found _WP-pin description ?
Hardware reference manual ADSP-BF51x_hwr_rev1.2.pdf and
can't help me...
Thanks for your time.