The nice feature with the 219x is that it uses 16 bits rather than 14
bits for addressing.
On the 2191, there is 32K of program memory at 24bit width (0x0000-
0x8000) and 32K of data memory at 16bit width (0x8000-0xFFFF). ADI
says 160k bytes of memory on their website
(24/8*32K+16/8*32K0KBYTES). The memory is unified unlike the 8x
What kind of algorithms are you needing? 64K minimum? of what? If
you keep code and data in the DSP you'll run faster. The 2191 has
memDMA which allows you do move data from one location to another
with a DMA controller. You could use this feature to move data/code
in/out of the dsp to/from external memory when needed.
I'd have to take a look at the datasheets for both the dsp and the
ram your using to determine if you need to insert waitstates. The
write and read times are dependent on the clk your using. Whose 8
nsec SRAMS are you using?
Check out chp14 and Appendix B of the hardware user's Manual. There
should be 5 registers for external memory access control for the
waitstates.... ms1ctl ms0ctl ms3ctl ms2ctl bmsctl..
-Extended Write hold
-1/2/4/8/16/32 <=wait state counter clk based on some division of the
HCLK<= might want to check that in the manual....
-up to 7 wait states for RD and WR... there is a count value for WR
and RD that you can use per chip select.
--- In , Jeff Brower <jbrower@s...> wrote:
> Thanks Tim. Without an overlay mode (C54xx) or remapping feature
> onchip program memory is limited to 48k for 218x and 32k for 219x.
Somehow I thought
> 219x had more onchip program memory than that. For most of the
> combinations) we are running, we need 64k minimum.
> If we were using 8 nsec SRAMs, at what speed can we run these
processors and obtain
> zero wait-state external program memory access?
> Jeff Brower
> DSP sw/hw engineer
> Signalogic > "twd2950 " wrote:
> > > What's the most onchip memory that a 218x or similar ADI 16-bit
> > fixed-point device
> > > has internal?
> > > Jeff Brower
> > > DSP sw/hw engineer
> > > Signalogic
> > I believe the 2188 has the largest internal memory for the 8x
> > (48K at 24bit width<program memory> and 56K at 16bit width<data
> > memory>). The 2191 has the largest internal memory for the 9x
> > at 24bit width and 32K at 16bit width) and has the ability to
> > externally address 254 pages of 64KW or 64KB memory (or 256 pages
> > you change a bit to use BMS~... in order to access page 0/FF off
> > rather than on chip). also The instruction pointer on the 9x is 16
> > bits rather than 14bits... but there isn't a hardware overlay
> > feature....
> > Tim D