4570 Datasheet, PDF (28/69 Pages) Renesas Technology Corp – SINGLE-CHIP 4-BIT CMOS MICROCOMPUTER

MITSUBISHI MICROCOMPUTERS
4570 Group
SINGLE-CHIP 4-BIT CMOS MICROCOMPUTER
Machine cycle
f(XIN) (divided by 3)
“H”
“L”
TW3A
instruction
Timer 3 start
w
Timer 3
2 1 0 3 2 1 0 2 1 0 3 2 1 0 2 1 0 Timer 3 reload register R3H 0316
Timer 3 reload register R3L 0216
R3H
R3L R3H
R3L
“1”
Timer 3 underflow “0”
“H”
CARRY “L”
“L” interval “H” interval “L” interval “H” interval
set by set by R3H set by set by R3H
R3L
R3L
CARRY
“H”
“L”
Port CARR output
“H”
“L”
“a”
“b”
“1”
Timer 1 underflow “0”
Timer 1 start
w
“c”
“d”
(C20)
1
Interval “a” is set
by timer 1
Interval “b” is set by
reload register R1
Interval “c” is set by
reload register R1
Interval “d” is set by
reload register R1
Carrier wave output start
CARRY
“H”
“L”
Port CARR output
“H”
“L”
“1”
Timer 1 underflow “0”
Register C20
“1”
“0”
Carrier wave output start
Fig. 22 Carrier wave output auto-control by timer 1
(C20) 0
(C20) 1 (C20) 0 (C20) 1
27