M37212 Mitsubishi, M37212 Datasheet - Page 75

• Manufacturer Part Number: M37212
• Description: SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER for VOLTAGE SYNTHESIZER
• Manufacturer: Mitsubishi

8.14 DISPLAY OSCILLATION CIRCUIT
The OSD oscillation circuit has a built-in clock oscillation circuits, so
that a clock for OSD can be obtained simply by connecting an LC, an
RC, a ceramic resonator, or a quartz-crystal oscillator across the pins
OSC1 and OSC2. Which of the sub-clock or the OSD oscillation cir-
cuit is selected by setting bits 0 and 1 of the CRT clock selection
register (address 00ED
Fig. 8.14.1 Display Oscillation Circuit
8.15 AUTO-CLEAR CIRCUIT
When a power source is supplied, the auto-clear function will oper-
ate by connecting the following circuit to the RESET pin.
Fig. 8.15.1 Auto-clear Circuit Example
Rev. 1.0
Circuit example 1
Circuit example 2
Note : Make the level change from “L” to “H” at the point at
which the power source voltage exceeds the specified
voltage.
16
C1
OSC1
).
RESET
L
OSC2
RESET
C2
M37212M4/M8–XXXSP, M37212M6–XXXSP/FP
Vcc
Vss
Vcc
Vss
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER for VOLTAGE SYNTHESIZER
8.16 ADDRESSING MODE
The memory access is reinforced with 17 kinds of addressing modes.
Refer to SERIES 740 <Software> User’s Manual for details.
8.17 MACHINE INSTRUCTIONS
There are 71 machine instructions. Refer to SERIES 740 <Soft- ware>
User’s Manual for details.
9. PROGRAMMING NOTES
• The divide ratio of the timer is 1/(n+1).
•
•
•
•
Even though the BBC and BBS instructions are executed imme-
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.
After the ADC and SBC instructions are executed (in the decimal
mode), one instruction cycle (such as an NOP) is needed before
the SEC, CLC, or CLD instruction is executed.
An NOP instruction is needed immediately after the execution of
a PLP instruction.
In order to avoid noise and latch-up, connect a bypass capacitor
( 0.1 F) directly between the V
CNV
SS
pin, using a thick wire.
with ON-SCREEN DISPLAY CONTROLLER
MITSUBISHI MICROCOMPUTERS
M37212EFSP/FP
CC
pin–V
SS
pin and the V
CC
pin–
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