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[DPRG] C Compiler

Subject: [DPRG] C Compiler
From: Kipton Moravec kip at kdream.com
Date: Thu Aug 28 17:00:02 CDT 2003

Don't forget that logic will have to be included in the timing for the SRAM 
and Flash memory speed.  If it is a 74HC type part it could add 12-ns 
(check the exact part for certain) which means you would need faster flash 
and SRAM parts or slower clock speed.

I am not trying to be arguementative. I just want to make sure you know the 

I look up a MC68332 as another option $9-$12

Look also at the Dragonball processor. (MC68EZ328) Huge memory space and is 
glueless for DRAM and FLASH. C compuler is free (GNU)
Damn, is going obsolete.  $4.98 price...

O.K. the MC68VZ328   $7-8 or
MC68SZ328 $10.

The newer Dragonball processors are ARM Risc based.  I do not know about 
the tools for it.

Just to throw some more wrinkles into the mess.


At 04:13 PM 8/28/03, you wrote:
>True, the flash will have to be in data space in order to program it. It
>should be a simple matter though to toggle one I/O pin which switches
>the flash to code or data space using some glue logic. The XA could
>power up internally, check the checksum of the flash program, and then
>transfer execution to external code memory. If the bootloader mode is
>triggered, the internal XA program will execute the serial loader,
>transfer the flash to data memory, and write the flash. Data space could
>be provided for this purpose via. The on chip ram. External data space
>would not be available during flash write, but it shouldn't matter.
>Philips has an App mote on this application. App Note AN97019.
>Rick J. Bickle
>Integrated Control Systems
>Voice:  (972) 522-1593
>Fax:    (972) 660-7950
>Mail:   PO BOX 541058
>         Grand Prairie, TX. 75054-1058
>Email:  rbickle at intconsys.com
>Web:    www.intconsys.com
>-----Original Message-----
>From: dprglist-admin at dprg.org [mailto:dprglist-admin at dprg.org] On Behalf
>Of Kipton Moravec
>Sent: Thursday, August 28, 2003 3:09 PM
>To: Rick J. Bickle
>Cc: DPRG List
>Subject: RE: [DPRG] C Compiler
>For the XA using external flash for program memory, you have to have the
>hardware to logically move the flash from the program to data space in
>Harvard architecture to write to the flash.  You need another program
>for the code to write to the flash while you are writing the flash.  You
>can't generally run from the flash when you are programming from it.
>code space can be the internal code space of the XA.
>There are usually timing diagrams in the electrical part of the
>datasheet.  It will allow you to calculate the speed of program memory
>SRAM for the clock rate you are planning to use.   You need to know the
>number of nanoseconds from when the chip address lines have a full valid
>address, AND the chip select is enabled (usually low), and the data is
>ready to be read (usually) read strobe going high.
>If the chip select is direct from the processor no problem.  If the chip
>select goes through other logic you have to subtract the propagation
>through the logic from the number of nanoseconds.
>If you need specific help let me know and I can walk you through it.
>At 12:56 PM 8/28/03, you wrote:
> >I was just investigating the details of flash memory. Anyone have any
> >experience in handling flash memory? I was thinking of adding 256Kx8 of
> >flash, and writing a loader program which would receive serial code
> >data and load the flash in the system. This would increase my code
> >space from 64K to 256K, and potentially make updating the firmware
> >easier for the end user.
> >
> >Another question on another topic:
> >
> >Does anyone have a good definitive method for determining the necessary
> >RAM or EPROM speed for a given clock speed of microcontroller? I have
> >always done a rough calculation based on the BUS speed for a given
> >frequency, but am wondering if there is a better way.
> >
> >Thanks,
> >Rick J. Bickle
> >Integrated Control Systems
> >Voice:  (972) 522-1593
> >Fax:    (972) 660-7950
> >Mail:   PO BOX 541058
> >         Grand Prairie, TX. 75054-1058
> >Email:  rbickle at intconsys.com
> >Web:    www.intconsys.com
> >
> >
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