HX512K trick: fast-forward
Jasper_M
Posts: 222
Seeking in the 64+-region is slow, but with counters it can be a little faster:
EDIT: 0. Program the SRAM to be in auto-increment mode [noparse];)[/noparse]
1. Set a counter to DUTY CYCLE mode (Duty cycle is very deterministic as no PLL is involved), FRQx=1<<31
(This way it outputs 40Mhz frequency, twice the MIPS of Propeller)
2. Set OUTA and DIRA as if you were reading
3. Do the following loop:
EDIT: 0. Program the SRAM to be in auto-increment mode [noparse];)[/noparse]
1. Set a counter to DUTY CYCLE mode (Duty cycle is very deterministic as no PLL is involved), FRQx=1<<31
(This way it outputs 40Mhz frequency, twice the MIPS of Propeller)
2. Set OUTA and DIRA as if you were reading
3. Do the following loop:
mov r0, #NUMBER_OF_BYTES_TO_FAST_FORWARD/2-2
movs ctra, #SRAM_STROBE 'ENABLE OUTPUT ON SRAM CLOCK STROBE
loop djnz r0, #loop
movs ctra, #0 'Disable output
Comments
can't wait to get my mits on a 512k to have a play with it too, and join in the fun.
Yeah, the more the merrier ^_^ ... wonder how many HX512K:s are out there?
--or some hit games to drive sales [noparse];)[/noparse]
All of us core people will end up with one at some poiint, so maybe our works will drive others.
A bit like Sega's 32X which was a great little add on, but just didn't quite make the grade.