[avr-libc-dev] AT90USB1287 start of ExtSRAM in XML file

[Daren.Yeo]

The XML file for AT90USB1287 seems to be in error.
The external RAM starting address is set to $2200, but the part manual
lists it at $2100.
Got no response from Atmel regarding this issue. Anyone else find it to
be true? 
 
________________________________

From: Yeo, Daren (NAUSCT) 
Sent: Thursday, May 24, 2007 12:33 PM
To: 'address@hidden'
Subject: AT90USB1287 start of ExtSRAM in XML file


AVR Studio 4 V4.13 b528
uP: AT90USB1287
In:   Atmel\AVR Tools\Partdescriptionfiles\AT90USB1287.xml

<MEMORY>
    <ID>AVRSimMemory8bit.SimMemory8bit</ID>
    <PROG_FLASH>131072</PROG_FLASH>
    <EEPROM>4096</EEPROM>
    <INT_SRAM>
        <SIZE>8192</SIZE>
        <START_ADDR>$100</START_ADDR>
    </INT_SRAM>
    <EXT_SRAM>
        <SIZE>65536</SIZE>
        <START_ADDR>$2200</START_ADDR>
    </EXT_SRAM>
 
But in AT90USB646_ds.pdf:

5. AVR AT90USB64/128 Memories This section describes the different
memories in the AT90USB64/128. The AVR architecture has two main memory
spaces, the Data Memory and the Program Memory space. In addition, the
AT90USB64/128 features an EEPROM Memory for data storage. All three
memory spaces are linear and regular. Notes: 1. Byte address. 2. Word
(16-bit) address. 5.1 In-System Reprogrammable Flash Program Memory The
AT90USB64/128 contains 128K bytes On-chip In-System Reprogrammable Flash
memory for program storage. Since all AVR instructions are 16 or 32 bits
wide, the Flash is organized as 64K x 16. For software security, the
Flash Program memory space is divided into two sections, Boot Program
section and Application Program section. The Flash memory has an
endurance of at least 100,000 write/erase cycles. The AT90USB64/128
Program Counter (PC) is 16 bits wide, thus addressing the 128K program
Table 5-1. Memory Mapping. Memory Mnemonic AT90USB64 AT90USB128 Flash
Size Flash size 64 K bytes 128K bytes Start Address - 0x00000 End
Address Flash end 0x0FFFF(1) 0x7FFF(2) 0x1FFFF(1) 0xFFFF(2) 32 Registers
Size - 32 bytes Start Address - 0x0000 End Address - 0x001F I/O
Registers Size - 64 bytes Start Address - 0x0020 End Address - 0x005F
Ext I/O Registers Size - 160 bytes Start Address - 0x0060 End Address -
0x00FF Internal SRAM Size ISRAM size 4 K bytes 8 K bytes Start Address
ISRAM start 0x0100 End Address ISRAM end 0x10FF 0x20FF External Memory
Size XMem size 0-64 K bytes Start Address XMem start 0x2100 End Address
XMem end 0xFFFF EEPROM Size E2 size 2 K bytes 4K bytes Start Address -
0x0000 End Address E2 end 0x07FF 0x0FFF

I think at the XML file should have the starting address of extSRAM as
2100, instead of 2200.
Please advise, thanks,
 
Daren Yeo
Sr. Software Engr. 
Gerber Scientific Products - A Gerber Scientific Company
83 Gerber Road 
South Windsor, Connecticut USA 
860.648.8159
address@hidden <mailto:address@hidden>