Application Note for D25 1Gb LPDDR4 Chip ID Read Function

1. PREFACE

Winbond D25 1Gb LPDDR4 is designed with a function called as Chip ID Read (CIDR) function for

customer to identify the unique ID of each chip.

Further to the datasheet, this application note discloses the detail description of CIDR function for

customer easy to use the function for purpose requested by specific application.

2. OPERATION SEQUENCE OF CHIP ID READ FUNCTION

CIDR function is able to be enabled as below sequence after power up.

2.1 Chip ID Enable Sequence:

The chip ID read function must be enabled before chip ID readout. The chip ID enable sequence is

executed after power on. It must be executed consecutive MR9 with different OP code. The deselect

command must be executed after each MR9. Following is the CIDR enable sequence.

2.2 Chip ID Read Sequence:

Once CIDR function is enabled, follow Chip ID read sequence, the chip ID will be read out by consecutive

MR9 with different OP code. deselect command must be executed after each MR9. The Mode Register

Read (MRR) command is used to read configuration and status data from the LPDDR4-SDRAM registers.

The mode register contents are available on the first 8UI's data bits of DQ[0]. Each MRR group is 32 data

bits, Total 96 data bits can be readout by 3 group. Following is the Chip ID read sequence.

2.3 Chip ID Disable Sequence

The Chip ID disable sequence be excused after chip ID readout. It must be executed consecutive MR9 with

different OP code. The deselect command must be executed after each MR9, Following is the CIDR enable

sequence.

2.4 Chip ID decode

The chip ID code is valid from 0 to 72 bit when chip ID code be readout, and those bits after the 73th bit are

don’t care. 10 of the 72 bits are invalid code with ECC. The table shown as below is the decode rule when

chip ID being readout.

3. MEASUREMENT OF CHIP ID READ SEQUENCE BY MOSAID TESTER

The CHIP ID is correctly readout under below conditions.

4. REVISION HISTORY

The above information is the exclusive intellectual property of Winbond Electronics and shall not be disclosed, distributed or reproduced without permission from Winbond.