![](http://datasheet.mmic.net.cn/380000/-PD78196Y_datasheet_16744919/-PD78196Y_80.png)
CHAPTER 5 EEPROM
80
Figure 5-2. Format of EEPROM Write Control Register 0
Notes 1.
Bits 1 and 3 are read-only.
2.
To select output of the 8-bit timer (TM80) with the count clock, enable output of TM80 in advance (by
setting bit 0 of TOE80 (8-bit timer mode control register 80 (TMC80)) to 1).
Caution
ERST0 is 0 during a reset, immediately after a reset, in STOP mode, and immediately after
release of STOP mode. However, ERST0 is set to 1 when a certain oscillation settling time has
elapsed.
ERST0 = 0 when ERE0 is set to 0, while EWST0 = 1, and during standby release time in the case
the value of ERE0 is changed from 0 to 1.
Remarks 1.
f
X
: Main system clock oscillation frequency (ceramic/crystal oscillation)
2.
f
CC
: Main system clock oscillation frequency (RC oscillation)
3.
f
XT
: Subsystem clock oscillation frequency, the parenthesized values apply to operation at f
XT
=
32.768 kHz.
0
EWCS02 EWCS01 EWCS00
ERST0
ERE0
EWST0
EWE0
EEWC0
Symbol
Address
After Reset
R/W
FFCCH
04H
R/W
6
7
<0>
5
4
<3>
<2>
<1>
EWCS02 EWCS01 EWCS00
EEPROM Timer Count Clock Selection
f
X
/2
3
(625 kHz)
f
X
/2
4
(313 kHz)
f
X
/2
5
(156 kHz)
f
X
/2
6
(78.1 kHz)
f
X
/2
7
(39.1 kHz)
f
X
/2
8
(19.5 kHz)
8-bit timer (TM80) output
Note 2
f
XT
(32.768 kHz)
f
CC
/2
3
(500 kHz)
f
CC
/2
4
(250 kHz)
f
CC
/2
5
(125 kHz)
f
CC
/2
6
(62.5 kHz)
f
CC
/2
7
(31.3 kHz)
f
CC
/2
8
(15.6 kHz)
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
ERE0
EWE0
Write
Read
Remarks
EEPROM is in the standby state (low power consumption mode).
0
1
×
0
1
Disabled
Disabled
Enabled
Disabled
Enabled
Enabled
EWST0
EEPROM Write Status Flag
Data is not being written to the EEPROM. (Data can be written to or read from the EEPROM. However,
the EEPROM cannot be written to when EWE = 0.)
0
1
ERST0
EEPROM Read Status Flag
Data cannot be read from the EEPROM.
Data can be read from the EEPROM.
0
1
Note 1
Data is being written to the EEPROM. (Data cannot be written to and read from the EEPROM.)
At f
X
= 5.0 MHz
At f
CC
= 4.0 MHz