DS2490Y Maxim Integrated Products, DS2490Y Datasheet - Page 25

• Manufacturer Part Number: DS2490Y
• Description: IC BRIDGE CLIP USB TO 1-W 24SOIC
• Manufacturer: Maxim Integrated Products

Specifications of DS2490Y

• Applications: USB
• Interface: 1-Wire
• Voltage - Supply: 3 V ~ 5.5 V
• Package / Case: 24-SOIC (7.5mm Width)
• Mounting Type: Surface Mount
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

WRITE SRAM PAGE—This command is used to write data to the scratchpad of an SRAM device and
optionally check the CRC. To copy the data to its final memory location, it is required to send the READ
STRAIGHT command with a “copy scratchpad” preamble and a 0 block size. Embedded command bit
DT = 1 activates the CRC16 generator. This command is also applicable to the Write IPR function of the
Crypto iButton if embedded command bit CIB = 1. To write a partial page the page size parameter and
the target address need to be set accordingly. The EP2 FIFO must be pre-filled with preamble and SRAM
data before command execution. Additionally, for data page sizes greater then the EP2 FIFO size, the
FIFO content status must be monitored by host SW so that additional data can be sent to the FIFO when
necessary.
Command parameters:
EP2 data:
EP3 data:
Result Register:
Command parameters:
EP2 data:
EP3 data:
Result Register:
If CIB = 0: 3-bytes + page
If CIB = 1: 2-bytes + page
1 byte specifying number of couplers that need to be activated to set-up
the path to the target device.
Length
9 bytes per
level
Length
1 byte
Code
CMP, SH,
NRS
0x00
None
None
1 byte specifying page size. This specifies the number of bytes to be
sent to the 1-Wire device following a 2- or 3-byte preamble. This
number is typically identical to the page size; a value of 0x00 indicates a
256-byte page.
Length
size
size
None
Code
CRC
0x00
None
None
25 of 50
Description
Preamble and data bytes to be sent to the 1-Wire
SRAM device. 3-byte preamble: 1-Wire command
code, TA1, TA2 (typical).
Preamble and data bytes to be sent to the 1-Wire
SRAM device. 2-byte preamble: 1-Wire command
code, length information.
Description
8 bytes ROM ID of the coupler to be activated
followed by the Smart-On command code for either
the main or auxiliary 1-Wire coupler output.
Description
Number of couplers successfully activated; should be
the same as the number of levels.
Condition
ICP = 0, NTF = 0 or 1: An error condition is detected.
ICP = 0, NTF = 1: no error detected
ICP = 0, NTF = 0: no error detected
ICP = 1
Condition
ICP = 0, NTF = 0 or 1: and an error condition (only if
DT = 1).
ICP = 0, NTF = 1: no error detected
ICP = 0, NTF = 0: no error detected
ICP = 1