Method for identification of SPI compatible serial memory devices

• US 20040085822A1
• Filed: 10/30/2002
• Published: 05/06/2004
• Est. Priority Date: 10/30/2002
• Status: Active Grant

• Current Assignee: Artemis Acquisition LLC (Renesas Electronics Corporation)
• Original Assignee: Atmel Corporation (Microchip Technology Incorporated)
• Inventors: DeCaro, Richard V.
• Granted Patent: US 7,032,039 B2
• Time in Patent Office: Days
• US Class Current: 365/200
• CPC Class Codes: G11C 2216/30 Reduction of number of input/output pins by using a serial interface to transmit or receive addresses or data, i.e. serial access memory
• CPC Class Codes: G11C 7/10 Input/output [I/O] data interface arrangements, e.g. I/O data control circuits, I/O data buffers
• CPC Class Codes: G11C 7/20 Memory cell initialisation circuits, e.g. when powering up or down, memory clear, latent image memory

Abstract

A method for identifying Serial Peripheral Interface (SPI) compatible serial interface memory devices. A microprocessor sends a single command requesting identification information to an SPI device installed on the SPI bus. A byte string, including the JEDEC manufacturer ID, device ID, and any extended device information, is sent back to the microprocessor. The byte string may include one or more continuation codes when the manufacturer ID exceeds 1 byte. The byte string also includes one byte indicating how many bytes of extended device information should be read by the microprocessor. The identification process, issuing the command and receiving the reply, is completed in one operation.

Claims

1. A method for identifying a serial peripheral interface compatible serial interface memory device comprising:

a) sending a clocked command to the device, the command requesting manufacturer and device information; and

b) receiving a clocked reply from the device, the reply identifying;

i) the manufacturer of the device;

ii) device data;

iii) a length of an extended information string, wherein the string contains vendor specific information about the device; and

iv) extended vendor specific information about the device, if any, wherein identifying the device is completed in one operation.

2. The method of claim 1 wherein the reply identifies the device using a vendor specific format.

3. The method of claim 1 wherein the reply identifies a JEDEC manufacturer identification.

4. The method of claim 3 further comprising the reply providing at least one continuation code for identifying a JEDEC manufacturer identification.

5. The method of claim 1 wherein the reply identifies the manufacturer of the device in “

n”

bytes.

6. The method of claim 1 wherein the reply identifies the device data in two bytes.

7. A method for identifying a serial peripheral interface compatible serial interface memory device comprising:

a) requesting manufacturer and device information from the device using a single clocked command; and

b) receiving a clocked byte string of variable length including the requested information and any extended vendor specific information from the device, wherein requesting and receiving the information is completed in one operation.

8. The method of claim 7 wherein receiving the requested information further comprises reading the requested information.

9. The method of claim 8 wherein the byte string identifies the manufacturer of the device.

10. The method of claim 8 wherein the byte string identifies device data.

11. The method of claim 8 wherein the byte string identifies a length of an extended information string, wherein the string contains vendor specific information about the device.

12. The method of claim 10 further comprising identifying device data with a vendor specific format.

13. The method of claim 9 further comprising identifying the manufacturer of the device with a JEDEC manufacturer identification.

14. The method of claim 13 further comprising using at least one continuation code for providing a JEDEC manufacturer identification.

15. The method of claim 7 wherein the byte string identifies the manufacturer of the device in “

n”

bytes.

16. The method of claim 7 wherein the byte string identifies the device data in two bytes.