On-chip peripherals
10.1.9 Control register (WDGCR)
WDGCR
7
6
5
4
WDGA
R/W
3
T[6:0]
R/W
ST72324xx-Auto
Reset value: 0111 1111 (7Fh)
2
1
0
Table 35. WDGCR register description
Bit Name
Function
Activation bit
duct(s) 7 WDGA
This bit is set by software and only cleared by hardware after a reset. When
WDGA = 1, the watchdog can generate a reset.
0: Watchdog disabled
1: Watchdog enabled
Note: This bit is not used if the hardware watchdog option is enabled by option byte.
ro 7-bit counter (MSB to LSB)
lete P 6:0 T[6:0]
These bits contain the value of the Watchdog counter, which is decremented every
16384 fOSC2 cycles (approx.). A reset is produced when it rolls over from 40h to 3Fh
(T6 is cleared).
bso Table 36. Watchdog timer register map and reset values
O Address (Hex.) Register label 7
6
5
4
3
2
1
0
t(s) - 002Ah
WDGCR
WDGA T6 T5 T4 T3 T2 T1 T0
reset value
0
1
1
1
1
1
1
1
Obsolete Produc 10.2
Main clock controller with real-time clock and beeper
(MCC/RTC)
The main clock controller consists of three different functions:
● a programmable CPU clock prescaler
● a clock-out signal to supply external devices
● a real-time clock timer with interrupt capability
Each function can be used independently and simultaneously.
10.2.1
Programmable CPU clock prescaler
The programmable CPU clock prescaler supplies the clock for the ST7 CPU and its internal
peripherals. It manages Slow power saving mode (see Section 8.2: Slow mode on page 53
for more details).
The prescaler selects the fCPU main clock frequency and is controlled by three bits in the
MCCSR register: CP[1:0] and SMS.
70/193
Doc ID 13841 Rev 1