UPD77113A View Datasheet(PDF) - NEC => Renesas Technology

Part Name

Description

Manufacturer

UPD77113A

16-BIT FIXED-POINT DIGITAL SIGNAL PROCESSORS

NEC => Renesas Technology 

µPD77113A, 77114

5.3 Signature Operation

The µPD77113A and 77114 have a signature operation function so that the contents of the internal instruction

RAM can be verified. The signature operation performs a specific arithmetic operation on the data in the instruction

RAM booted up, and returns the result to a register. Perform the signature operation in advance on the device when

it is operating normally, and repeat the signature operation later to check whether the data in RAM is correct by

comparing the operation result with the previous result. If the results are identical, there is no problem.

The entry address is 0x9. Execute the operation by calling this address after setting the following parameter. The

operation result is stored in register R7.

• R7L: Number of instruction steps for operation

• DP3: First address of instruction memory for operation

5.4 Instruction ROM Modification

The µPD77113A and 77114 have a function to modify the contents of the internal instruction mask ROM.

Instructions at up to four addresses can be modified.

The entry address is 0x10D. By calling this address with the following parameters, modification is performed.

R7L

: Address of instruction ROM to be modified

R6H, R6L : Instruction code (32 bits)

Data Sheet U14373EJ3V0DS

23

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