tmp89fm42k TOSHIBA Semiconductor CORPORATION, tmp89fm42k Datasheet - Page 46

• Manufacturer Part Number: tmp89fm42k
• Description: 8 Bit Microcontroller Tlcs-870/c1 Series
• Manufacturer: TOSHIBA Semiconductor CORPORATION

2.3
System clock controller
RA000
2.3.5
2.3.5.1
external high-frequency and external low-frequency clocks, and switches the main system clock (fm).
modes are controlled by the system control registers (SYSCR1 and SYSCR2).
Operation mode control circuit
The operation mode control circuit starts and stops the oscillation circuits for the internal high-frequency,
There are three operating modes: the single-clock mode, the dual-clock mode and the STOP mode. These
Figure 2-9 shows the operating mode transition diagram.
is stopped and the counter is cleared.
WUCCR<WUCRST> is cleared to "0".
is set to "1". To restart the warm-up operation, SYSCR2<XEN> or SYSCR2<XTEN> must be cleared to "0".
is 1/fcgck [s].
the internal high-frequency clock (fosc).
(XIN) and P01 (XOUT) of the external high-frequency clock oscillation circuit can be used as general-purpose
I/O ports.
When the upper 8 bits of the counter become equal to WUCDR, an INTWUC interrupt occurs, counting
Set WUCCR<WUCRST> to "1" to discontinue the warm-up operation.
By setting it to "1", the count-up operation is stopped, the warm-up counter is cleared, and
SYSCR2<OSCEN>, SYSCR2<XEN> and SYSCR2<XTEN> hold the values when WUCCR<WUCRST>
Only the gear clock (fcgck) is used for the operation in the single-clock mode.
The main system clock (fm) is generated from the gear clock (fcgck). Therefore, the machine cycle time
The gear clock (fcgck) is generated from the high-frequency reference clock (fh).
The high-frequency reference clock (fh) can be selected from the external high-frequency clock (fc) and
When the internal high-frequency clock (fosc) is used as the high-frequency reference clock (fh), pins P00
Single-clock mode
Note:The warm-up counter starts counting when SYSCR2<OSCEN>, SYSCR2<XEN> or SYSCR2<XTEN>
Note:The clock output from the oscillation circuit is used as the input clock to the warm-up counter. The
is changed from "0" to "1". The counter will not start counting by writing "1" to SYSCR2<XEN> or
SYSCR2<XTEN> when it is in the state of "1".
warm-up time contains errors because the oscillation frequency is unstable until the oscillation circuit
becomes stable. Set the sufficient time for the oscillation start property of the oscillator.
<WUCSEL>
WUCCR
00
01
10
<WUCDIV>
WUCCR
00
01
10
11
00
01
10
11
00
01
10
11
Counter input
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fosc / 2
fosc / 2
fosc / 2
fc / 2
fc / 2
fs / 2
fs / 2
clock
fc / 2
fs / 2
fosc
fc
fs
2
3
2
3
2
3
2
2
2
2
6
7
8
9
2
2
2
2
2
2
2
2
/ fosc to 255 x 2
/ fosc to 255 x 2
/ fosc to 255 x 2
/ fosc to 255 x 2
6
7
8
9
6
7
8
9
/ fc to 255 x 2
/ fc to 255 x 2
/ fc to 255 x 2
/ fc to 255 x 2
/ fs to 255 x 2
/ fs to 255 x 2
/ fs to 255 x 2
/ fs to 255 x 2
Warm-up time
6
7
8
9
6
7
8
9
6
7
8
9
/ fosc
/ fosc
/ fosc
/ fosc
/ fc
/ fc
/ fc
/ fc
/ fs
/ fs
/ fs
/ fs
TMP89FM42K