3807 Datasheet, PDF (8/75 Pages) Renesas Technology Corp – SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER

MITSUBISHI MICROCOMPUTERS
3807 Group
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER
FUNCTIONAL DESCRIPTION
Central Processing Unit (CPU)
The 3807 group uses the standard 740 family instruction set. Refer
to the table of 740 family addressing modes and machine instruc-
tions or the SERIES 740 <Software> User´s Manual for details on
the instruction set.
Machine-resident 740 family instructions are as follows:
The FST and SLW instructions cannot be used.
The MUL, DIV, WIT and STP instruction can be used.
The central processing unit (CPU) has the six registers.
CPU Mode Register
The CPU mode register contains the stack page selection bit and
processor mode bits. The CPU mode register is allocated at address
003B16.
b7
Fig. 5. Structure of CPU mode register
b0
CPU mode register
(CPUM : address 003B16)
Processor mode bits
b1 b0
0 0 : Single-chip mode
0 1 : Memory expansion mode
1 0 : Microprocessor mode
1 1 : Not available
Stack page selection bit
0 : 0 page
1 : 1 page
XCOUT drivability selection bit
0 : Low drive
1 : High drive
Port XC switch bit
0 : I/O port function (stop oscillating)
1 : XCIN-XCOUT oscillating function
Main clock (XIN-XOUT) stop bit
0 : oscillating
1 : stopped
Main clock division ratio selection bits
b7 b6
0 0 : φ = f(XIN)/2 (high-speed mode)
0 1 : φ = f(XIN)/8 (middle-speed mode)
1 0 : φ = f(XCIN)/2 (low-speed mode)
1 1 : Not available
7