M38203M4 Datasheet, PDF (5/344 Pages) Mitsubishi Electric Semiconductor – 8-BIT SINGLE-CHIP MICROCOMPUTER

BEFORE USING THIS USER’S MANUAL
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.
1. Organization
q CHAPTER 1 HARDWARE
This chapter describes features of the microcomputer, operation of each peripheral function and electric
characteristics.
q CHAPTER 2 APPLICATION
This chapter describes usage and application examples of peripheral functions, based mainly on setting examples
of related registers.
q CHAPTER 3 APPENDIX
This chapter includes precautions for systems development using the microcomputer, a list of control registers,
the masking confirmation forms (mask ROM version), ROM programming confirmation forms (One Time PROM
version) and mark specification forms which are to be submitted when ordering.
2. Structure of register
The figure of each register structure describes its functions, contents at reset, and attributes as follows :
Bits
Bit attributes (Note 2)
b7 b6 b5 b4 b3 b2 b1 b0
Values immediately after reset release (Note 1)
1
CPU mode register (CPUM) [Address:3B 16]
B
Name
0 Processor mode bits
1
2 Stack page selection bit
3 _{Fix this bit to “1.”}
4 Port XC switch bit
5 Main clock (XIN–XOUT) stop bit
6 Main clock division ratio
selection bit
7 _{Internal system clock selection bit}
Functions
At reset
b1b0
00: Single-chip mode
0
01:
10: Not available
11:
0
0 : 0 page
1 : 1 page
0
1
0 : I/O port
1 : XCIN, XCOUT
0
0 : Oscillating
1 : Stopped
0
0 : f(XIN)/2
((hhiigghh--ssppeeeedd mmooddee))
1
1 : f(XIN)/8
(middle-speed mode)
0 : XIN-XOUT selected
(middle-/high-speed mode)
0
1 : XCIN-XCOUT selected
(low-speed mode)
RW
11
!
: Bit in which nothing is allocated
: Bit that is not used for control of the corresponding function
Notes 1: Values immediately after reset release
0••••••“0” at reset release
1••••••“1” at reset release
?••••••Undefined or reset release
2: Bit attributes••••••The attributes of control register bits are classified into 3 types : read-only, write-only
and read and write. In the figure, these attributes are represented as follows :
R••••••Read
••••••Read enabled
! ^{••••••Read disabled}
0 ^{••••••Fixed to “0”}
1 ^{••••••Fixed to “1”}
W ••••••Write
••••••Write enabled
! ^{••••••Write disabled}
V ^{••••••Only “0” write enabled}
0 ••••••Fix to “0”
1 ••••••Fix to “1”