UPD784026 Renesas Electronics Corporation., UPD784026 Datasheet - Page 654

• Manufacturer Part Number: UPD784026
• Description: 16/8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

614
Cautions 1. When crystal/ceramic oscillation is used, the EXTC bit of the oscillation stabilization time
OSTS
EXTC
2. If the STOP mode is used when using external clock input, the EXTC bit must be set (1) before
7
Figure 22-4 Oscillation Stabilization Time Specification Register (OSTS) Format
specification register (OSTS) must be cleared (0) before use. If the EXTC bit is set (1), oscillation
will stop.
setting STOP mode. If the STOP mode is used with the EXTC bit cleared (0) the PD784026 may
suffer damage or reduced reliability.
When setting the EXTC bit of OSTS to 1, be sure to input a clock in phase reverse to that of the
clock input to the X1 pin, to the X2 pin (refer to 4.3.1 Clock Oscillator).
6
0
5
0
4
0
CHAPTER 22 STANDBY FUNCTION
3
0
OSTS2
2
OSTS1
1
OSTS0
EXTC
EXTC OSTS2
0
0
0
0
0
0
0
0
1
0
1
0
External Clock Selection
When crystal/ceramic oscillation is used
When external clock is used
Address
0FFCFH
0
0
0
0
1
1
1
1
OSTS1
0
0
1
1
0
0
1
1
On Reset
OSTS0
00H
0
1
0
1
0
1
0
1
Oscillation Stabilization
Time Selection Bits
2
2
2
2
2
2
2
2
512/f
R/W
R/W
20
19
18
17
16
15
14
13
/f
/f
/f
/f
/f
/f
/f
/f
XX
XX
XX
XX
XX
XX
XX
XX
XX
41.9 ms
21.0 ms
10.5 ms
5.24 ms
2.62 ms
1.31 ms
655 s
328 s
(When f
20.5 s
XX
=25 MHz)