ST72T774J9B1 STMicroelectronics, ST72T774J9B1 Datasheet - Page 18

• Manufacturer Part Number: ST72T774J9B1
• Manufacturer: STMicroelectronics

Specifications of ST72T774J9B1

• Cpu Family: ST7
• Device Core Size: 8b
• Frequency (max): 24MHz
• Interface Type: I2C/USB
• Program Memory Type: EPROM
• Program Memory Size: 60KB
• Total Internal Ram Size: 1KB
• # I/os (max): 31
• Number Of Timers - General Purpose: 1
• Operating Supply Voltage (typ): 5V
• Operating Supply Voltage (max): 5.5V
• Operating Supply Voltage (min): 4V
• On-chip Adc: 1-chx8-bit
• On-chip Dac: 1-chx8-bit
• Instruction Set Architecture: CISC
• Operating Temp Range: 0C to 70C
• Operating Temperature Classification: Commercial
• Mounting: Through Hole
• Pin Count: 42
• Package Type: SPDIP
• Lead Free Status / Rohs Status: Specific Sites Compliant

ST72774/ST727754/ST72734
3 CLOCKS, RESET, INTERRUPTS & LOW POWER MODES
3.1 CLOCK SYSTEM
3.1.1 General Description
The MCU accepts either a crystal or an external
clock signal to drive the internal oscillator. The
internal clock (CPU CLK running at f
derived from the external oscillator frequency
(f
external quartz or clock frequency, a division factor
of 2 is optionally added to generate the 12 MHz
clock for the Sync Processor (clamp function) as
Figure 7. Clock divider chain
18/144
4
OSC
12 MHz
or
24MHz
), which is divided by 3. Depending on the
FAST=1 for 24MHZ oscillator
OSC
%2
FAST
CPU
FAST=0 for 12 MHz oscillator
) is
%2
shown in
6MHz USB clock.
The CPU clock is used also as clock for the
ST727x4 peripherals.
Note: In the Sync processor, an additional divider
by two is added in fast mode (same external timing
for this peripheral).
%3
(Sync processor Clampout signal)
12 MHz
Figure 7
(CPU and peripherals)
12 MHz
or
24MHz
(TMU)
6 MHz
(USB)
f
CPU
and a second divider by 2 for the
: 4 or 8 MHz