Chapter 6
MIPS® Malta™ User’s Manual, Revision 01.07 45
Copyright © 2000-2007 MIPS Technologies Inc. All rights reserved.
1284 Flash Download Format
The Malta Board’s Flash memory can be programmed and reprogrammed using a download cable that connects
directly to a PC parallel port. The CBUS FPGA can read data from this port and execute the appropriate erase/write
cycles in the Flash. The PC must be configured so that its printer port is set to “Generic - text only”, to avoid unpre-
dictable escape sequences being sent. The file format is a sequence of ASCII encoded hex bytes as described below.
How to download:
• Connect the parallel cable between the PCs parallel port, and J6 on the Malta.
• Switch S5-1 on the Malta to ON or CLOSED.
• Switch both PC and Malta ON.
• Run the download script to dump the file to the parallel port on the PC or workstation.
• Switch S5-1 to OFF, and reset Malta.
• Disconnect the parallel cable.
According to the memory map in Chapter 3, “Memory Map” on page 13, the Monitor Flash is programmed on base
address 0x1E00.0000 or 0x1FC0.0000. If any address outside the Flash is addressed the attempt will be ignored.
Note: When programming the address 1FC0.0010 it is the Monitor Flash that is being programmed, but when reading
the address it is overridden and does NOT decode to an address in Flash, but rather to register address REVISION.
The only way to read the programmed value back is to read the “non-boot” Monitor Flash address, ie. address
0x1E00.0010. See Chapter 3, “Memory Map” on page 13.
The Malta Board’s Flash devices are organised in sectors of 64 Kbyte. “Erase” and “Set Lock Bit” commands operate
on exactly one sector, this being the sector currently addressed. After the last block of 16 words in a sector are written
into flash, the address counter has advanced to the next sector. This implies that a Set Address (@) to the sector has to
be executed before a Set Lock Bit command (!S) can be issued.
The file to be loaded into the Flash via the 1284 port has the following format:
The download codes, shown in Table 6.1, are used to control code download and Flash memory handling:
Type: ASCII hex (both lower- and uppercase letters are accepted).
White space: Any characters below or equal to 20h are ignored (character 20h (space) is
allowed in the Print command. After the character 1Bh (start of a printer ini-
tialisation command) it ignores any character until next Reset Command.
Word width: 32 bits (data has to be in blocks of 16 words and has to be placed on 16 word
boundaries).
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