DS64BR111 Datasheet, PDF (17/39 Pages) Texas Instruments – Ultra Low Power 6.4 Gbps 2-Channel Repeaters with Input Equalization and Output De-Emphasis

EEPROM Modes in DS64BR111 Device
The DS64BR111 device supports reading directly from an
external EEPROM device by implementing SMBus Master
mode. When using the SMBus master mode, the DS64BR111
will read directly from specific location in the external EEP-
ROM. When designing a system for using the external EEP-
ROM, the user needs to follow these specific guidelines.
• Set the DS64BR111 into SMBus Master Mode
— Float ENSMB (PIN 3)
• The external EEPROM device address byte must be
0xA0'h
• Set the AD[3:0] inputs for SMBus address byte. When the
AD[3:0] = 0000'b, the device address byte is B0'h.
• Based on the SMBus 2.0 specification, a device can have
a 7-bit slave address of 1011 000'b. The LSB is set to 0'b
(for a WRITE). The bit mapping for SMBus is listed below:
— [7:5] = Reserved Bits from the SMBus specification
— [4:1] = Usable SMBus Address Bits
— [0] = Write Bit
• The DS64BR111 devices have AD[3:0] inputs in SMBus
mode (pins 1, 2, 9, 10). These pins set SMBus slave
address. The AD[3:0] pins do not have any internal pull
resistors. When the AD[3:0] = 0001'b, the device address
byte is B2'h.
— [7:5] = 4b'101
— [4:1] = Address of 4'b0001
— [0] = Write Bit, 1'b0
• The device address can be set with the use of the AD[3:0]
input up to 16 different addresses. Use the example below
to set each of the SMBus addresses.
— AD[3:0] = 0001'b, the device address byte is B2'h
— AD[3:0] = 0010'b, the device address byte is B4'h
— AD[3:0] = 0011'b, the device address byte is B6'h
— AD[3:0] = 0100'b, the device address byte is B8'h
• The master implementation in the DS64BR111, support
multiple devices reading from 1 EEPROM. When tying
multiple devices to the SDA and SCL pins, use these
guidelines:
— Use adjacent SMBus addresses for the 4 devices
— Use a pull-up resistor on SDA; value = 4.7KΩ
— Use a pull-up resistor on SCL: value = 4.7KΩ
— Daisy-chain READEN# (pin 17) and DONE# (pin18)
from one device to the next device in the sequence
1. Tie READEN# of the 1st device in the chain (U1)
to GND
2. Tie DONE# of U1 to READEN# of U2
3. Tie DONE# of U2 to READEN# of U3
4. Tie DONE# of U3 to READEN# of U4
5. Optional: Tie DONE# of U4 to a LED to show each
of the devices have been loaded successfully
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