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RE: Re: Silly question about ARM thumb
- From: Ian Campbell <icampbell at arcom dot com>
- To: ecos-discuss at ecos dot sourceware dot org
- Date: Wed, 23 Feb 2005 11:49:02 +0000
- Subject: RE: [ECOS] Re: Silly question about ARM thumb
- Organization: Arcom Control Systems
- References: <BAY12-F207AE3B40C8CAE4AC94780AD630@phx.gbl>
On Wed, 2005-02-23 at 07:47 +0000, Michael Anburaj wrote:
> Hi,
>
> It is possible to see some improvement in performance with Thumb mode when
> the core does not have cache (fetching each instruction off the external
> memory) & the bus size is 16 bits. Obviously, for Thumb mode each
> instruction fetch needs a single external memory read, where as ARM mode
> requires 2 reads.
is it also the case that on a system with a 32 bit bus that 2
consecutive thumb instructions can be fetched in a single external
memory read?
Ian.
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Ian Campbell, Senior Design Engineer
Web: http://www.arcom.com
Arcom, Clifton Road, Direct: +44 (0)1223 403 465
Cambridge CB1 7EA, United Kingdom Phone: +44 (0)1223 411 200
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