Methods for read retries and apparatuses using the same

• US 10,199,108 B2
• Filed: 10/06/2016
• Issued: 02/05/2019
• Est. Priority Date: 09/05/2016
• Status: Active Grant

• Current Assignee: Shannon Systems Ltd.
• Original Assignee: Shannon Systems Ltd.
• Inventors: Zhou, Zhen
• Primary Examiner(s): Abraham, Esaw T
• Application Number:
  US15/286,829
• Publication Number:
  US 20180068734A1
• Time in Patent Office: 852 Days
• CPC Class Codes: G06F 11/1048 using arrangements adapted for a specific error detection or correction feature
• CPC Class Codes: G06F 11/1068 in sector programmable memories, e.g. flash disk G06F11/1072 takes precedence
• CPC Class Codes: G06F 11/141 for bus or memory accesses
• CPC Class Codes: G06F 11/1417 Boot up procedures
• CPC Class Codes: G06F 9/4401 Bootstrapping security arrangements therefor G06F21/57
• CPC Class Codes: G11C 16/20 Initialising; Data preset; Chip identification
• CPC Class Codes: G11C 16/26 Sensing or reading circuits; Data output circuits
• CPC Class Codes: G11C 2029/0411 Online error correction
• CPC Class Codes: G11C 29/52 Protection of memory contents; Detection of errors in memory contents

Abstract

The invention introduces a method for read retries, performed by a processing unit, including at least the following steps: in boot time, generating and storing microcodes of a retry-read operation in an instruction buffer; and after a successful boot, receiving a retry-read command from a host device through a first access interface; and starting a state machine to execute the microcodes of the retry-read operation of the instruction buffer.

Claims

1. A method for read retries, performed by a processing unit, comprising:

during boot time, generating and storing microcodes of a retry-read operation in an instruction buffer by;

obtaining a flash ID (identity) associated with a storage unit;

reading one of a plurality of records, which corresponds to the flash ID, from a non-volatile memory, wherein each record comprises a plurality of retry parameters; and

generating the retry-read microcodes according to the retry parameters; and

after a successful boot, receiving a retry-read command from a host device through a first access interface; and

starting a state machine to execute the microcodes of the retry-read operation of the instruction buffer.

2. The method of claim 1, wherein the microcodes of the retry-read operation comprises retry-read microcodes of multiple iterations and a microcode of EOR (end of retry-read operation).

3. The method of claim 2, wherein the step of generating and storing microcodes of a retry-read operation in an instruction buffer comprises:

storing the retry-read microcodes in the instruction buffer; and

storing the microcode of EOR in the instruction buffer.

4. The method of claim 3, wherein the records are associated with different types of storage units, and the step of obtaining a flash ID (identity) associated with a storage unit comprises:

querying the storage unit to obtain the flash ID.

5. The method of claim 3, wherein the records are associated with different types of storage units, and the step of obtaining a flash ID (identity) associated with a storage unit comprises:

reading the flash ID from the non-volatile memory.

6. The method of claim 3, wherein the retry-read microcodes of each iteration comprises a first microcode comprising one retry parameter when being executed to set a register to direct a second access interface to read data, a second microcode when being executed to read data through the second access interface and store the data in a data buffer, a third microcode when being executed to direct an ECC (Error Check-and-Correction) unit to inspect the data, and a fourth microcode when being executed to determine whether to fetch and execute the microcode of EOR subsequently according to a replied message from the ECC unit.

7. The method of claim 6, wherein the fourth microcode comprises an address of the microcode of EOR.

8. The method of claim 7, wherein, when the fourth microcode is executed and the replied message indicates that the data is correct, the microcode of EOR is fetched according to the address.

9. The method of claim 8, wherein the microcode of EOR is executed to set the register to a default value and inform the processing unit the end of the retry-read operation to return control.

10. An apparatus for read retries, comprising:

an instruction buffer;

a state machine; and

a processing unit, coupled to the instruction buffer and the state machine, during boot time, generating and storing microcodes of a retry-read operation in the instruction buffer, wherein the processing unit;

obtains a flash ID (identity) associated with a storage unit;

reads one of a plurality of records, which corresponds to the flash ID, from a non-volatile memory, wherein each record comprises a plurality of retry parameters; and

generates the retry-read microcodes according to the retry parameters; and

after a successful boot, receiving a retry-read command from a host device through a first access interface; and

starting the state machine to execute the microcodes of the retry-read operation of the instruction buffer.

11. The apparatus of claim 10, wherein the microcodes of the retry-read operation comprises retry-read microcodes of multiple iterations and a microcode of EOR (end of retry-read operation).

12. The apparatus of claim 11, comprising:

a non-volatile memory,

wherein the processing unit stores the microcode of EOR in the instruction buffer.

13. The apparatus of claim 12, wherein the records are associated with different types of storage units, and the processing unit queries the storage unit to obtain the flash ID.

14. The apparatus of claim 12, wherein the records are associated with different types of storage units, and the processing unit reads the flash ID from the non-volatile memory.

15. The apparatus of claim 12, wherein the retry-read microcodes of each iteration comprises a first microcode comprising one retry parameter when being executed to set a register to direct a second access interface to read data, a second microcode when being executed to read data through the second access interface and store the data in a data buffer, a third microcode when being executed to direct an ECC (Error Check-and-Correction) unit to inspect the data, and a fourth microcode when being executed to determine whether to fetch and execute the microcode of EOR subsequently according to a replied message from the ECC unit.

16. The apparatus of claim 15, wherein the fourth microcode comprises an address of the microcode of EOR.

17. The apparatus of claim 16, wherein, when the fourth microcode is executed and the replied message indicates that the data is correct, the state machine fetches the microcode of EOR according to the address.

18. The apparatus of claim 17, wherein, when executing the microcode of EOR, the state machine sets the register to a default value and informs the processing unit the end of the retry-read operation to return control.