[Sdcc-user] Using sdcc with Cypress USB firmware

[Lanier, P. <pau...@an...>]

Hello,
	I've recently begun porting my firmware for a Cypress USB chip (FX2)
to sdcc.  I was originally using the tools from Keil Software that came with
it but they had a 4K code limit (on a chip with 8K memory) and they wanted
$1600 to upgrade.  I was very thankful to find an open source compiler was
available.  Anyway, most of the transition has been pretty smooth so far.  I
haven't actually tried the code out but I've got 90% of it to compile.  I
just have a few problems left in compiling, then I'll have to sort out the
memory mapping.

-First, does anyone have any documentation on the asx8051 assembler.  The
syntax is different than that of the Keil assembler.  All I need is info on
all the assembler directives available (like .area, etc.) and how they work
so it may not even need to be asx8051 specific (i.e. Is there a commercial
assembler that uses similar syntax?).

-Second, the frameworks code written by Cypress to handle the USB functions
uses a jump table for USB interrupts.  I'm not sure exactly sure how they
got the Keil compiler to do things right but the basic idea is that the jump
table is written in assembler and then all the interrupts are labeled in the
c source as "interrupt 0".  Any ideas on how to get this to work correctly
with sdcc?  I've attached the assembler for the jump table and the c file
where the interrupt procedures were declared.

-Third, has anyone else ever used sdcc with Cypress ezusb chips?  Any
problems I should look out for?

Thanks,

Paul Lanier

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Paul Lanier        
Product Development Engineer
Analog Devices
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