Errata Sheet - Infineon

Errata Sheet
Functional Deviations
return execution to the first instruction of the trap handler - where it will now
execute to completion without undesired interruption. If the interrupted traps are
considered recoverable but are time sensitive and need to be executed
immediately, then some method of deferring the interrupt processing is
required. If the test of the situation (e.g. checking the PCXI.PIE bit is clear) is
at the start of the Interrupt handler, then there are two simple methods to
consider:
The first method would be to re-request the interrupt, by writing the appropriate
Service Request Control Register with the SETR bit set to one, and then
executing an RFE which will be taken back to the trap handler. The interrupt will
now be pending again, but will not be taken until the trap handler executes its
RFE to re-enable interrupts. This method is simple if the device (and hence it's
SRC register address) generating the interrupt is known. If this is not easy to
determine (statically or dynamically), the second method might be preferred.
The second method would be to jump to the trap handler, after setting the trap
identification number (TIN) and the return address (which the trap handler will
use) to be the next instruction in the interrupt handler. This relies on the fact that
the CSA saved away by the preemption of the trap handler is equally valid as
an execution context for the interrupt handler. The code for this method is as
follows:
interruptN:
mfcr d15, PCXI
jnz.t d15, 23, interruptReal
; force CSA into memory
dsync
sh.h d14, d15, #12
insert d15, d14, d15, #6, #16
mov.a a15, d15
; load trap value of d15 from CSA
ld.w d15, [a15]0x3C
mov.a a15, a11
movh.a a11, #@his(interuptReal)
lea a11, [a11]@los(interruptReal)
; jump to trap handler, will return to interruptReal
ji a15
TC1767, EES-AD, ES-AD, AD 24/73 Rel. 1.4, 11.12.2009