Operating instructions

25-4
SCSI REFERENCE 1012975
CHAPTER 25—WRITE BUFFER (3Bh)
 The functional code resides in the remainder of the EEPROM (040000h
through 0FFFFFh) and is divided into six equal sections each corresponding
to a Buffer ID, as shown in Table 25-1.
Each of section of the functional code must be downloaded separately to the
autoloader’s buffer and then programmed to the EEPROM. For example, to
download section 2 (Buffer ID 02h), use the WRITE BUFFER command to send
bytes 04000h through 05FFFFh of the microcode update file to bytes 000000h
to 01FFFFh of the buffer. Similarly, for section 3 (Buffer ID 03h), send bytes
060000h to 07FFFFh of the microcode update file to bytes 000000h to 01FFFFh
of the buffer.
You can use one or more WRITE BUFFER commands to download a section of
the function code in the microcode update file to the buffer and program it
into the EEPROM. For each WRITE BUFFER command you issue, make sure
that you do the following:
 The sections of the functional code must be downloaded to the buffer and
programmed to the EEPROM sequentially, from Buffer ID 02 to Buffer
ID 07h.
 If you use multiple WRITE BUFFER commands, set the Mode bit to 100b
(Write microcode to buffer but do not save it to EEPROM) for the all but the
last WRITE BUFFER command in the download sequence.
 For the final WRITE BUFFER command in the download sequence or if you
use only one WRITE BUFFER command to download the whole section at
once, set the Mode bit to 101b (Write microcode to buffer and save entire
buffer to EEPROM).
 Use the Buffer ID to specify the section of microcode being downloaded.
 When using multiple WRITE BUFFER commands to download a section of
the microcode, use the Buffer Offset to specify the location in the buffer to
write the data. Usually the Buffer Offset is the sum of all the Parameter List
Lengths used in the sequence of WRITE BUFFER command used to transfer
to the section of microcode.
When using a single WRITE BUFFER command to download an entire
section of the microcode, set the Offset Buffer to 00h.
Table 25-1 Buffer IDs and byte locations of functional code sections
Section Buffer ID Byte location
2 02h 040000h through 05FFFFh
3 03h 060000h through 7FFFFh
4 04h 08000h through 9FFFFh
5 05h 0A000h through BFFFFh
6 06h 0C0000h through DFFFFh
7 07h 0E0000h through 0FFFFFh