ST62T42B ST Microelectronics, ST62T42B Datasheet - Page 25

• Manufacturer Part Number: ST62T42B
• Description: 8-BIT OTP/EPROM MCU WITH LCD DRIVER / EEPROM AND A/D CONVERTER
• Manufacturer: ST Microelectronics

DIGITAL WATCHDOG (Cont’d)
These instructions test the C bit and Reset the
MCU (i.e. disable the Watchdog) if the bit is set
(i.e. if the Watchdog is active), thus disabling the
Watchdog.
In all modes, a minimum of 28 instructions are ex-
ecuted after activation, before the Watchdog can
generate a Reset. Consequently, user software
Figure 14. Digital Watchdog Block Diagram
S
RSFF
RESET
Q
R
DB0
DB 1.7
8
WRITE
DATA BUS
-2
LOAD
7
RESET
SET
should load the watchdog counter within the first
27 instructions following Watchdog activation
(software mode), or within the first 27 instructions
executed following a Reset (hardware activation).
It should be noted that when the GEN bit is low (in-
terrupts disabled), the NMI interrupt is active but
cannot cause a wake up from STOP/WAIT modes.
SET
-2
8
OSCILLATOR
CLOCK
-12
VA00010
ST62T42B/E42B
25/68
25