W25B40 Datasheet, PDF (25/36 Pages) Winbond – 4M-BIT SERIAL FLASH MEMORY WITH BOOT AND PARAMETER SECTORS

W25B40/W25B40A
8.2.14 Read Manufacturer / Device ID (90h)
The Read Manufacturer/Device ID instruction is an alternative to the Release from Power-down /
Device ID instruction that provides both the JEDEC assigned manufacturer ID and the specific device ID.
The Read Manufacturer/Device ID instruction is very similar to the Release from Power-down / Device
ID instruction. The instruction is initiated by driving the /CS pin low and shifting the instruction code
“90h” followed by a 24-bit address (A23-A0) of 000000h. After which, the Manufacturer ID for Winbond
(EFh) and the Device ID are shifted out on the falling edge of CLK with most significant bit (MSB) first
as shown in figure 16. The Device ID values for the W25B40 / W25B40A are listed in Manufacturer
and Device Identification table. If the 24-bit address is initially set to 000001h the Device ID will be
read first and then followed by the Manufacturer ID. The Manufacturer and Device IDs can be read
continuously, alternating from one to the other. The instruction is completed by driving /CS high.
Figure 16. Read Manufacturer / Device ID Diagram
- 25 -
Publication Release Date: January 6, 2006
Revision M