M37221 Mitsubishi, M37221 Datasheet - Page 55

• Manufacturer Part Number: M37221
• Description: SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER for VOLTAGE SYNTHESIZER with ON-SCREEN DISPLAY CONTROLLER
• Manufacturer: Mitsubishi

DISPLAY OSCILLATION CIRCUIT
The CRT display clock oscillation circuit has a built-in clock oscilla-
tion circuits, so that a clock for CRT display can be obtained simply
by connecting an LC, an RC, a ceramic resonator or a quartz-crystal
oscillator circuit across the pins OSC 1 and OSC 2. Select the clock
for display with bits 0 and 1 of the CRT clock selection register (ad-
dress 00ED
Fig. 63. Display oscillation circuit
Fig. 64. Auto-clear circuit example
AUTO-CLEAR CIRCUIT
When power source is supplied, the auto-clear function can be per-
formed by connecting the following circuit to the RESET pin.
Circuit example 2
Note : Make the level change from “L” to “H” at the point at
Circuit example 1
16
which the power source voltage exceeds the specified
voltage.
).
C1
OSC1
RESET
L
RESET
OSC2
C2
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER for VOLTAGE SYNTHESIZER
Vcc
Vcc
Vss
Vss
M37221EF-XXXSP,M37221EFSP
ADDRESSING MODE
The memory access is reinforced with 17 kinds of addressing modes.
Refer to the SERIES 740 <Software> User’s Manual for details.
MACHINE INSTRUCTIONS
There are 71 machine instructions. Refer to the SERIES 740 <Soft-
ware> User’s Manual for details.
PROGRAMMING NOTES
(1) The divide ratio of the timer is 1/(n+1).
(2) Even though the BBC and BBS instructions are executed imme-
(3) After the ADC and SBC instructions are executed (in decimal
(4) An NOP instruction is needed immediately after the execution of
(5) In order to avoid noise and latch-up, connect a bypass capacitor
diately after the interrupt request bits are modified (by the pro-
gram), those instructions are only valid for the contents before
the modification. At least one instruction cycle is needed (such as
an NOP) between the modification of the interrupt request bits
and the execution of the BBC and BBS instructions.
mode), one instruction cycle (such as an NOP) is needed before
the SEC, CLC, or CLD instruction is executed.
a PLP instruction.
( 0.1 F) directly between the V
CNV
SS
pin using a thick wire.
with ON-SCREEN DISPLAY CONTROLLER
CC
pin–V
SS
pin and the V
CC
pin–
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