HD4074329S Renesas Electronics America, HD4074329S Datasheet - Page 41

• Manufacturer Part Number: HD4074329S
• Description: MCU 4-Bit HMCS400 CISC 20KB EPROM 3.3V/5V 64-Pin SDIP
• Manufacturer: Renesas Electronics America

Specifications of HD4074329S

• Package: 64SDIP
• Family Name: HMCS400
• Maximum Speed: 4.5 MHz
• Ram Size: 268 Byte
• Program Memory Size: 20 KB
• Operating Supply Voltage: 3.3|5 V
• Data Bus Width: 4 Bit
• Program Memory Type: EPROM
• Number Of Programmable I/os: 35
• On-chip Adc: 4-chx8-bit
• Operating Temperature: -20 to 75 °C
• Number Of Timers: 3

Internal Oscillator Circuit
A block diagram of the internal oscillator circuit is shown in figure 22. As shown in table 21, crystal and
ceramic oscillators can be connected to OSC
X1 and X2. The system oscillator can also be operated by an external clock. Bit 3 of the miscellaneous
register (MIS: $00C) must be set according to the frequency of the oscillator connected to OSC
Note: If the MIS register setting does not match the oscillator frequency, subsystems using 32-kHz
OSC
OSC
X1
X2
2
1
Miscellaneous register (MIS): $00C
oscillation will malfunction. Set the system oscillator frequency to anything outside the range of
1.0 MHz to 1.6 MHz when using 32-kHz oscillation.
3
Sub-system
2
oscillator
oscillator
System
1
0
Figure 22 Internal Oscillator Circuit
Figure 21 Miscellaneous Register
Divide-by-8
Divide-by-8
R1 /SO PMOS off
Setting for switching
the system oscillator’s
frequency
2
circuit
circuit
Initial value: 0000,
R/W: W
1
and OSC
t
RC
selection
generator
generator
2
, and a 32.768-kHz oscillator can be connected to
Timing
Timing
circuit
circuit
Synch.
(t
Synch.
(t
Bit 3
MIS
subcyc
cyc
0
1
)
)
1.6 MHz to 4.5 MHz
0.4 MHz to 1.0 MHz
System Oscillator’s
Frequency
control
Mode
circuit
HD404328 Series
Time-base
clock
(
1
ø
and OSC
System
clock
(
System
clock
(
CLK
ø
ø
CPU
PER
)
)
)
37
2
.