BEFORE USING THIS USER’S MANUAL
1. Manual Contents
This user’s manual consists of the following three chapters. Refer to the chapter appropriate to your conditions,
such as hardware design or software development.
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CHAPTER 1 – HARDWARE
This chapter describes the features of the microcomputers, the operation of their peripherals, and
their electrical characteristics.
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CHAPTER 2 – APPLICATIONS
This chapter describes usage of peripheral functions and application examples of the microcomputers,
focusing on the settings of the related registers.
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CHAPTER 3 – APPENDICES
This chapter describes all the control register configurations, and the mask ROM confirmation forms
(mask ROM version), the ROM programming confirmation forms (one time PROM version), and the
mark specification forms to be submitted at the ordering.
2. Register Configurations
An example of control register configurations of the 7480 Group and 7481 Group and the description of
symbols used in them are explained below.
b5
b6
b7
b4 b3 b2 b1 b0
b
Name
Function
At reset
1
2
3
4
5
6
7
0
Undefined
0
Undefined
Fix these bits to ‘0’
Stack page selection bit
(Note)
0 : Zero page
1 : 1 page
Watchdog timer L count
source selection bit
0 : f(XIN)/8
1 : f(XIN)/16
Clock division
ratio selection bit
0 : f(XIN)/2 (high-speed mode)
1 : f(XIN)/8 (medium-speed mode)
Not implemented. Writing to this bit is disabled.
This bit is undefined at reading.
Not implemented. Writing to this bit is disabled.
This bit is undefined at reading.
Note: In the products whose RAM size is 192 bytes or less, set this bit to ‘0’.
0
Not implemented. Writing to this bit is disabled.
This bit is undefined at reading.
Undefined
RW
O
0
O
Undefined
×
O0
OO
0
Notes 1: Contents after system is released from reset
0: ‘0’ after system is released from reset
1: ‘1’ after system is released from reset
undefined: undefined after system is released from reset
2: Bit attributes
R (Read)
O: Read enabled
×: Read disabled
Undefined: Undefined at reading
0: ‘0’ at reading
1: ‘1’ at reading
O: Write enabled
×: Write disabled
0: Fixed to ‘0’
: This bit can be set to ‘0’ by software, but cannot be set to ‘1’.
W (Write)
indicates the bit which is not implemented.
Bit
Bit attributes (Note 2)
Contents immediately after system is released from reset (Note 1)
CPU mode register (CPUM) [Address 00FB16]