tmp89fm42a TOSHIBA Semiconductor CORPORATION, tmp89fm42a Datasheet - Page 45

• Manufacturer Part Number: tmp89fm42a
• Description: 8 Bit Microcontroller
• Manufacturer: TOSHIBA Semiconductor CORPORATION

2.3
System clock controller
RA000
2.3.4
Internal high-frequency
clock (fosc)
External high-frequency
clock (fc)
External low-frequency
clock (fs)
2.3.4.1
quency clock (fc) and the external low-frequency clock (fs), and it consists of a source clock selection circuit, a
3-stage frequency division circuit and a 14-stage counter.
becomes stable and secure the time after the STOP mode is released or the operation mode is changed before the
oscillation by the oscillation circuit becomes stable.
Warm-up counter
The warm-up counter is a circuit that counts the internal high-frequency clock (fosc), the external high-fre-
The warm-up counter is used to secure the time after a power-on reset is released before the supply voltage
(1)
Warm-up counter operation when the oscillation is enabled by the hardware
voltage becomes stable and the time after a reset is released before the oscillation by the high-frequency
clock oscillation circuit becomes stable.
warm-up counter reset signal is released. At this time, the CPU and the peripheral circuits are held in
the reset state.
selects the internal high-frequency clock (fosc) as the input clock to the warm-up counter.
the warm-up counter, and the 14-stage counter starts counting the internal high-frequency clock (fosc).
reset is released for the CPU and the peripheral circuits.
The warm-up counter serves to secure the time after a power-on reset is released before the supply
When the power is turned on and the supply voltage exceeds the power-on reset release voltage, the
A reset signal initializes WUCCR<WUCSEL> to "00" and WUCCR<WUCDIV> to "11", which
When a reset is released for the warm-up counter, the internal high-frequency clock (fosc) is input to
When the upper 8 bits of the warm-up counter become equal to WUCDR, counting is stopped and a
When a power-on reset is released or a reset is released
corresponds to one main system clock.
ranging from 1-cycle instructions, which require one machine cycle for execution, to 10-cycle
instructions, which require 10 machine cycles for execution, and 13-cycle instructions, which
require 13 machine cycles for execution.
A
B
C
S
Z
The minimum instruction execution unit is called a "machine cycle". One machine cycle
There are a total of 11 different types of instructions for the TLCS-870/C1 Series: 10 types
Figure 2-8 Warm-up Counter Circuit
WUCSEL
1 2 3
2
WUCDIV
WUCCR
2
D
C
B
A
S
2
Z
Page 26
WUCRST
Enable/disable counting up
1 2 3 4 5 6 7 8 9 10 11 12 13 14
XEN XTEN
Warm-up counter
SYSCR2
controller
1 2 3 4 5 6 7 8
OSCEN
WUCDR
Comp-
arator
STOP
INTWUC interrupt request
Enable CPU operation
SYSCR1
TMP89FM42A