If the host receives the CRC16 value, the host can compare this value to the expected computed value. If there

is a match, the write scratchpad communication is successful and the host can decide to proceed to the Copy

Scratchpad command.

If the host does not receive the CRC16 value, then the host can use the Read Scratchpad command to verify

integrity of the data stored in the scratchpad. After the Read Scratchpad command is received, the TMF0008

initially transmits the contents of the target address registers (TA1, TA2) and the E/S register. If the PF flag is

set, or if the AA flag is set but PF flag cleared, the previous Write Scratchpad command is not successful. In

this case, the host can terminate the Read Scratchpad sequence and start another attempt to write data to the

scratchpad. If the previous Write Scratchpad is successful, both flags are cleared and the E[4:0] that is read

indicates the address of the last byte written to the scratchpad. In this case, the host can continue reading from

the TMF0008, verifying all the data bytes. If there is a match, the host can send the Copy Scratchpad command

followed by the exact data of the registers TA1, TA2, and E/S that the host obtained by reading the scratchpad.

At the end of the Copy Scratchpad sequence, if the authorization pattern matches, the TMF0008 starts copying

the scratchpad data to the requested location, provided copy protection is not set, the PF flag is cleared, and

there are no Read Memory or Extended Read Memory commands issued between Write and Copy Scratchpad

commands.

6.3.5 TMF0008 Device ID

The 64-bit ID identifies each TMF0008. The 48-bit serial number is unique and programmed by Texas

Instruments. The default Family code is 23h.

8b CRC

48-BIT SERIAL NUMBER

8b FAMILY CODE

MSB

LSB MSB

LSB MSB

LSB

Figure 6-4. 64-Bit Factory Programmed EPROM

6.3.6 Bus Termination

The drive output of the TMF0008 is an open-drain, N-channel MOSFET, for proper operation, a 500-Ω external

pullup resistor must be connected on the SDQ bus (see Figure 7-1).

6.4 Device Functional Modes

6.4.1 Test Procedures for Functional Tests

This section outlines the specific test procedures used to obtain the parameters listed in Functional Tests.

6.4.1.1 Multiple Responder Configurations

This test verifies the operation of the TMF0008 in a multi-drop use case. The host must be able to communicate

with multiple devices on the SDQ bus. The presence of other DUTs must not impact communication to the

selected DUT.

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TMF0008

SLVSIV3 – JULY 2025

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