DS2490 Datasheet, PDF (45/50 Pages) Dallas Semiconductor – USB to 1-Wire Bridge Chip

COMMUNICATION COMMANDS
wLength
0x0000
DS2490
WRITE EPROM
Setup Packet Encoding:
bmRequestType
bRequest
wValue
wIndex
wLength
READ CRC PROT PAGE
Setup Packet Encoding:
bmRequestType
bRequest
wValue
wIndex
wLength
READ REDIRECT PAGE
W/CRC
Setup Packet Encoding:
bmRequestType
bRequest
wValue
DT=1 selects the CRC16 generator. Otherwise an 8-bit CRC is
assumed. If Z=1 the comparison of the byte read back for verification
is limited to 0 bits only.
0x40
COMM_CMD
byte 2
byte 1
byte 2: 0 0 DT 0
F
0 ICP 0
byte 1: 1 1 0 0
Z
1 0 IM
byte 2
byte 1
byte 2 – block size (HI), number of bytes to be written, most
significant byte
byte 1 – block size (LOW), number of bytes to be written, least
significant byte
0x0000
DT=1 selects the CRC16 generator, otherwise an 8-bit CRC is
assumed. This command is also applicable to the Read IPR and Read
I/O Buffer function of the crypto iButton if CIB=1.
0x40
COMM_CMD
byte 2
byte 1
byte 2: 0 PS DT 0
F
0 ICP 0
byte 1: 1 1 0 1
0
1 0 IM
byte 2
byte 1
byte 2 –number of pages to be read.
byte 1 – page size: number of bytes that are considered a page.
Typical is 32-decimal for data memory, 8 for status memory, and 40
decimal for Monetary iButtons. Page size 0 indicates a 256-byte
page.
0x0000
0x40
COMM_CMD
byte 2
byte 2: 0 0 1 0
45 of 50
byte 1
F
0 ICP 1
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