EM78159NAS EMC [ELAN Microelectronics Corp], EM78159NAS Datasheet - Page 18

• Manufacturer Part Number: EM78159NAS
• Description: 8-Bit Microcontroller with OTP ROM
• Manufacturer: EMC [ELAN Microelectronics Corp]

EM78P159N
8-Bit Microcontrollerwith OTP ROM
14 •
4.2.8 IOCE (WDT Control Register)
Bit 7 (WDTE): Control bit used to enable the Watchdog timer.
Bit 6 (EIS):
Bit 5:
Bit 4 (ROC): ROC is used for the R-option.
Bit 3 (PSWE): Prescaler enable bit for WDT
Bit 2 (PSW2) ~ Bit 0 (PSW0): WDT prescaler bits
WDTE
Bit 7
Bit 6
Control bit is used to define the function of P60 (/INT) pin.
Not used
EIS
0 = Disable WDT
1 = Enable WDT
WDTE is both readable and writable.
0 = P60, bi-directional I/O pin.
1 = /INT, external interrupt pin. In this case, the I/O control bit of P60 (Bit
When EIS is "0," the path of /INT is masked. When EIS is "1," the status
of /INT pin can also be read by way of reading Port 6 (R6). See Figure
4-4a under Section 4.4 for reference.
EIS is both readable and writable.
Setting the ROC to "1" will enable the status of R-option pins (P50∼P51)
that are read by the controller. Clearing the ROC will disable the
R-option function. If the R-option function is selected, you must connect
the P51 pin or/and P50 pin to VSS with a 430KΩ external resistor (Rex).
If the Rex is connected/disconnected, the status of P50 (P51) is read as
"0" / "1." Refer to Figure 4-5 under Section 4.4 for reference.
0 = prescaler disable bit, WDT rate is 1:1.
1 = prescaler enable bit, WDT rate is set as Bit4~Bit2.
PSW2
0 of IOC6) must be set to "1."
0
0
0
0
1
1
1
1
Bit 5
-
PSW1
0
0
1
1
0
0
1
1
ROC
Bit 4
PSW0
(This specification is subject to change without further notice)
0
1
0
1
0
1
0
1
PSWE
Bit 3
Product Specification (V1.0) 03.10.2006
WDT Rate
1:128
1:256
1:16
1:32
1:64
1:2
1:4
1:8
PSW2
Bit 2
PSW1
Bit 1
PSW0
Bit 0