M37221M4H_15 Datasheet, PDF (79/114 Pages) Renesas Technology Corp – SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER for VOLTAGE SYNTHESIZER with ON-SCREEN DISPLAY CONTROLLER

M37221M4H/M6H/M8H/MAH–XXXSP/FP M37221EASP/FP
8.15 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 OSD clock selection
register (address 00ED16).
OSC1 OSC2
L
C1
C2
Fig. 8.15.1 Display Oscillation Circuit
8.16 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.
Circuit example 1
Vcc
RESET
Vss
8.17 ADDRESSING MODE
The memory access is reinforced with 17 kinds of addressing modes.
Refer to SERIES 740 <Software> User’s Manual for details.
8.18 MACHINE INSTRUCTIONS
There are 71 machine instructions. Refer to SERIES 740 <Soft- ware>
User’s Manual for details.
9. TECHNICAL 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
(≈ 0.1µF) directly between the VCC pin–VSS pin and the VCC pin–
CNVSS pin, using a thick wire.
• [Electric Characteristic Differences Between Mask ROM and One
Time PROM Version MCUs]
There are differences in electric characteristics, operation mar-
gin, noise immunity, and noise radiation between Mask ROM and
One Time PROM version MCUs due to the difference in the manu-
facturing processes. When manufacturing an application system
with the One time PROM version and then switching to use of the
Mask ROM version, please perform sufficient evaluations for the
commercial samples of the Mask ROM version.
Circuit example 2
Vcc
RESET
Vss
Note : Make the level change from “L” to “H” at the point at
which the power source voltage exceeds the specified
voltage.
Fig. 8.16.1 Auto-clear Circuit Example
Rev.1.00 Oct 01, 2002 page 77 of 110
REJ03B0134-0100Z