Posted 25 February 2011 - 12:58 PM
By order of flashing Cortex-M3 by through JTAG-DP i first read out the IDCODE. Now i try to access the MEM-AP.
Is it possible to access the whole System Memory by this way?
Here are the things i have done.
At first i wanted to read out the IDR to be shure to have access.
I allude to page 8-4 in ARM ® Debug Interface v5 Architecture Specification (ARM IHI 0031A).
- choose the DPACC in the IR-Scan
- write 0xf4 to DPACC in DR-Scan (SELECT: 0x0->AHB-AP(Mem-AP);0xf->APBANKSEL(Bank 0xF);0x2->A[3:2](AP Select);0->R/W(Write))
- choose the APACC in the IR-Scan
- write 0x7 to APACC in DR-Scan (0x0->DATA; 0x3->A[3:2](Identification Register(IDR));1->R/W(Read))
-go through the DR-Scan again for reading the IDR
Not sure with the RnW bit of the APACC because it points to Resource-specific transport and not to the MEM-AP.
In this way i can't read it out.
I'm just doing the legwork and for this we don't want to use any of the common programming devices.
thanks a lot
(if you have some time please allude to grammar mistakes to improve my english)