RX8804CE
Page - 17
ETM59E-05
8.3. SOUT Function
8.3.1. Various Function of SOUT
1) The flag value selected by FS bit can be outputted at SOUT pin. See SOUT Function program ex.1
By this function RTC inner self monitoring flag VDET, VLF are outputted at SOUT pin despite /INT pin.
Even user system sleep period, RTC can monitor inner status.
2) By setting DC bit, user can control SOUT pin output. See SOUT Function program ex.2.
By this function RTC SOUT pin can drive external device ex. LED.
8.3.2. SOUT Function Program ex.1
In case of V
DD
voltage drop SOUT pin outputs Low level. Signal.
Timing chart SOUT Function program is described step 1~ 7.
Figure 8 SOUT Function Program ex.1
STEP 1
operation
Disabling SOUT function
Command Example
WriteRX8804(19h,00h)
Target Address
19h
SOE7
SOE6
SOE5
SOE4
SOE3
SOE2
SOE1
SOE0
Write Data
00h
0
0
0
0
0
0
0
0
STEP 2
operation
Clearing VLF bit. Retaining UF, TF, AF, VDET bit
Command Example
WriteRX8804(0Eh,39h)
Target Address
0Eh
0
0
UF
TF
AF
0
VLF
VDET
Write Data
39h
0
0
1
1
1
0
0
1
STEP 3
operation
VLF is outputted to SOUT pin as low active
Command Example
WriteRX8804(1Ah,0Dh)
Target Address
1Ah
DCE
DC
0
0
SRV
FS2
FS1
FS0
Write Data
0Dh
0
0
0
0
1
1
0
1
STEP 4
operation
Enabling SOUT function
Command Example
WriteRX8804(19h,69h)
Target Address
19h
SOE7
SOE6
SOE5
SOE4
SOE3
SOE2
SOE1
SOE0
Write Data
69h
0
1
1
0
1
0
0
1
STEP 5
Low level is outputted at SOUT pin when V
DD
low is detected
STEP 6
operation
SOUT pin is switched to High level when VLF is cleared to 0
Command Example
WriteRX8804(0Eh,39h)
Target Address
0Eh
0
0
UF
TF
AF
0
VLF
VDET
Write Data
39h
0
0
1
1
1
0
0
1
STEP 7
operation
Disabling SOUT function
Command Example
WriteRX8804(19h,00h)
Target Address
19h
SOE7
SOE6
SOE5
SOE4
SOE3
SOE2
SOE1
SOE0
Write Data
00h
0
0
0
0
0
0
0
0
V
DD
1.0 V Typ.
VLF Flag
SOUT
Step 1 2 3 4 5 6 7,8,9 A B C D E
Program ex. 1
Hi-Z
Hi-Z