ST7232AJ2 STMicroelectronics, ST7232AJ2 Datasheet - Page 23

• Manufacturer Part Number: ST7232AJ2
• Description: 8-BIT MCU WITH 8K FLASH/ROM, ADC, 4 TIMERS, SPI, SCI INTERFACE
• Manufacturer: STMicroelectronics

Specifications of ST7232AJ2

• Hdflash Endurance: 100 cycles, data retention
• Clock Sources: crystal/ceramic resonator oscillators and bypass for external clock
• Four Power Saving Modes: Halt, Active-Halt, Wait and Slow
• Main Clock Controller With: Real time base, Beep and Clock-out capabilities
• Two 16-bit Timers With: 2 input captures, 2 output compares, PWM and pulse generator modes

6 SUPPLY, RESET AND CLOCK MANAGEMENT
The device includes a range of utility features for
securing the application in critical situations (for
example in case of a power brown-out), and re-
ducing the number of external components. An
overview is shown in
For more details, refer to dedicated parametric
section.
Main features
■
■
■
6.1 PHASE LOCKED LOOP
If the clock frequency input to the PLL is in the
range 2 to 4 MHz, the PLL can be used to multiply
Figure 11. Clock, Reset and Supply Block Diagram
– 5 Crystal/Ceramic resonator oscillators
Optional PLL for multiplying the frequency by 2
Reset Sequence Manager (RSM)
Multi-Oscillator Clock Management (MO)
RESET
OSC2
OSC1
V
V
SS
DD
Figure
OSCILLATOR
RESET SEQUENCE
MULTI-
(MO)
MANAGER
(RSM)
11.
f
OSC
(option)
PLL
SICSR
SYSTEM INTEGRITY MANAGEMENT
0
the frequency by two to obtain an f
MHz. The PLL is enabled by option byte. If the PLL
is disabled, then f
Caution: The PLL is not recommended for appli-
cations where timing accuracy is required.
Figure 10. PLL Block Diagram
f
OSC
0
PLL x 2
0
/ 2
OSC2 =
0
WDG
f
RF
OSC2
f
OSC
PLL OPTION BIT
/2.
CLOCK (MCC/RTC)
WITH REALTIME
0
1
TIMER (WDG)
CONTROLLER
MAIN CLOCK
WATCHDOG
OSC2
ST7232A
f
OSC2
of 4 to 8
23/157
f
CPU
1