CCS/TMS320F28020: Program address of interrupts in C28x CPU

Phu Nguyen,

On F2802x, XINT1 is routed through the PIE so you will have to set up the interrupt vector table with your ISR address in address 0x0D46. There is more work to do than simply assigning the address.

Unfortunately I am not allowed to post CCS projects, but to give you an idea, an assembly code example of initializing the PIE table is below.

; copy PIE vector table into RAM
SETC VMAP ; enable PIE vector table
MOVW DP, #PIECTRL>>6 ; load data page
OR @PIECTRL, #01b ; enable PIE vector table [ENPIE = 1]
MOVW DP, #_vectorTable ; load data page
MOVL XAR7, #_vectorTable ; XAR7 = source address
MOVL XAR0, #0x0D00 ; XAR0 = destination address [0x0D00]
RPT #255 ; repeat 256 times (vector table = 128 x 32-bit words)
|| PREAD *XAR0++, *XAR7 ; copy half-vector into RAM


...where PIECTRL is the address of the PIE control register:
PIECTRL .set 0CE0h

...and _vectorTable is the symbol at the start of your vector table, defined as:
.def _vectorTable ; vector table symbol

Your vector table would look something like this:

.label _PIE_vector_table_start
_vectorTable:
.long _UTRAP ; [0x0D00] reserved
.long _UTRAP ; [0x0D02] reserved
.long _UTRAP ; [0x0D04] reserved
.long _UTRAP ; [0x0D06] reserved

... more .longs ...

.long _UTRAP ; [0x0D44] reserved
.long _myIsr ; [0x0D46] XINT1
.long _UTRAP ; [0x0D48] XINT2

... and so on ...


This is just one thing: there is a lot more to do to configure and use the device from assembly, and you have to know what you're doing. Almost all C28x users are coding in C. Is there a reason you prefer to use assembly?

Regards,

Richard