Lpc2000

I'm using 16 bit wide Toshiba's SRAM (currently 1Mx16 - pcb supports upto 
16MB) and Toshiba's Flash (1Mx16 - pcb supports upto 16MB). They have 
different access times; 70ns and 90ns respectively. Each CS# line can be 
programmed to support different memory timings. So the external bus does not 
have fixed speed. Timings change as programmed for CS0#,CS1,CS2 and CS3# 
lines. Of course more chip select signal can be generated but will inherit 
the properties of one of the 4 cs lines unless you have an external hardware 
to work otherwise.

Few things to be aware of when interfacing external memory:

- Series termination would be considered for the data and address lines
- BL0# signal must be used for 8 bit devices as the uP never asserts WR# 
signal for 8 bit access.

I'have tested SRAM (read/write patterns) and Flash (read, program, chip 
erase, sector erase, etc.) at 60MHz and they both worked fine.

Hope this answers your questions.

Kerem

----- Original Message ----- 
From: "Gus" <gus_is_working@...>
To: <lpc2000@yahoogroups.com>
Sent: Tuesday, January 18, 2005 8:16 PM
Subject: [lpc2000] Re: LPC22XX usage


>
>
> I have ben using LPC21 for a while and now thinking about using
> LPC22 for a new project. Same as you, I would like to know if people
> haveing issues with it.
>
> - What RAM chips everyone is using?
> - What FLASH is used?
> - Anything else we should be aware as far as the external bus?
> - From my understanding, the external bus have a fixed speed for the
> whole address range, is this true? I mean, if we have fast RAM and
> slow FLASH on the same chip we would have to run the chip to the
> speed of the slow device (FLASH in this example.)
>
> Thanks,
>
> Gus
>
> --- In lpc2000@yahoogroups.com, "RW Concepts - enquiries"
> <enquiries@r...> wrote:
>> I've been looking at using an LPC22XX device as I want an external
> memory bus. The thing is I've never seen any postings about this
> range which leads me to think that everyone's using a 21XX device.
> This can't be the case, can it?
>>
>> TIA.
>>
>> Rog.
>>
>> [Non-text portions of this message have been removed]
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> Yahoo! Groups Links
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