upd75212a Renesas Electronics Corporation., upd75212a Datasheet - Page 18

• Manufacturer Part Number: upd75212a
• Description: 4-bit Single-chip Microcomputer
• Manufacturer: Renesas Electronics Corporation.

18
5.2
control register (SCC).
* Instruction execution
Remarks
The clock generator operations are determined by the processor clock control register (PCC) and the system clock
The clock generator has two types: main system clock and subsystem clock.
The instruction execution time can be changed.
0.95 s, 1.91 s, 15.3 s (Main system clock: at 4.19 MHz operation)
122 s (Subsystem clock: at 32.768 kHz operation)
CLOCK GENERATOR
HALT*
STOP*
4
1.
2.
3.
4.
5.
6.
7.
f
f
f
PCC: Processor clock control register
SCC: System clock control register
1 clock cycle (t
ELECTRICAL SPECIFICATIONS.
X
XT
XX
PCC2 and
PCC3
Clear
SCC3
SCC0
PCC0
PCC1
PCC2
PCC3
= CPU clock
SCC
PCC
= Main system clock frequency
= Subsystem clock frequency
= System clock frequency
XT1
XT2
X2
X1
Main System
Subsystem
Oscillator
Oscillator
Clock
Clock
CY
) of
Oscillation
Stop
STOP F/F
Q
Fig. 5-1 Clock Generator Block Diagram
is 1 machine cycle of an instruction. For t
f
f
X
S
R
XT
Watch Timer
Timer/Pulse
Generator
f
XX
1/2 1/6
Frequency Divider
1/8~1/4096
HALT F/F
S
R
CY
Q
, see ”AC Characteristics“ in 12.
• FIP Controller
• Basic Interval Timer (BT)
• Timer/Event Counter
• Serial Interface
• Watch Timer
• INT0 Noise Eliminator
Wait Release Signal from BT
RES Signal (Internal Reset)
Standby Release Signal from
Interrupt Control Circuit
• CPU
• INT0 Noise Eliminator
• INT1 Noise Eliminator
Frequency
Divider
1/4
PD75212A