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How to set the function set of ROM data of QzROM?

Latest Updated:10/10/2008

Question:

(QzROM)  Regarding the function set ROM (FSROM) data of QzROM:
(1) What are the initial values of the function set ROM data?
(2) Is the way to read/write the function set ROM the same as that of SFR?
(3) How do I set the function set ROM data by a program?
[2008/10/10]

Answer:

(1) The initial values of the function set ROM data are FFh.
Please be sure to set the value for the selected function for your system,
because the MCU will not operate correctly while the function set ROM data is set to FFh.

The QzROM values in function set ROM data 0 to 2 set the operating modes of the various peripheral functions after a MCU reset is released. Bits designated with a fixed value of 1 or 0 must be set to the designated value.

(2) No, because function set ROM data are located in ROM area, not the SFR registers which are located in RAM area.
The function set ROM can be read/written using a programmer, but cannot be changed by a user program after a MCU reset is released.

(3) Please refer to the following example for the 7548 Group:

Example:
.org $0FFD4
.BLKB 01H       ; Renesas shipment test area
.BLKB 01H       ; Renesas shipment test area
.BLKB 01H       ; Renesas shipment test area
.BLKB 01H       ; Renesas shipment test area
.BYTE 80H       ; Function Set ROM Data 0
.BYTE 81H       ; Function Set ROM Data 1
.BYTE 0BH       ; Function Set ROM Data 2
.BLKB 01H       ; ROM Code Protect

Please do not re-write the data of the shipment test areas.

(#107146)

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