Data transfer from SAI to DTCM using HPDMA not working
I am using a Nucleo-N657X0-Q board to prototype a data collection system that collects samples from an ADC connected to the SAI peripheral and places the results in RAM. If I use CPU AXI RAM0 as the destination this works correctly, but if I change the destination to DTCM all I get is a buffer full of zeroes.
According to chapter-17 of the ref manual, HPDMA1 AXI port has access to the DTCM and I am setting the DAP field of HPDMA-CH0 TR1 register to Port-0 as required (setting it wrong results in a DTEF interrupt).
I have RISAF 1 and RISAF 2 set as follows:
RISAF1->REG[0].CFGR = 0x00000000;
RISAF1->REG[0].CIDCFGR = 0x00FF00FF; /* RW for everyone */
RISAF1->REG[0].STARTR = 0;
RISAF1->REG[0].ENDR = 0xFFFFFFFF; /* all-encompassing */
RISAF1->REG[0].CFGR = 0x00000101; /* enabled, secure, unprivileged for everyone */
RISAF2->REG[0].CFGR = 0x00000000;
RISAF2->REG[0].CIDCFGR = 0x00FF00FF; /* RW for everyone */
RISAF2->REG[0].STARTR = 0;
RISAF2->REG[0].ENDR = 0xFFFFFFFF; /* all-encompassing */
RISAF2->REG[0].CFGR = 0x00000101; /* enabled, secure, unprivileged for everyone */
I have the channel 0 bits in both HPDMA_PRIVCFGR and HPDMA_SECCFGR set.
I also have added the following to the reset handler and can read and write to DTCM OK using the CPU.
ldr r0, =0x30000000
ldr r1, =0x30020000
mov r2,#0
clear_dtcm:
str r2,[r0]
add r0,r0,#4
cmp r0,r1
bcc clear_dtcm
The program is a secure domain only application.
Can anyone think of any other reason why this is not working?
Thanks
Nige