ST52T440F3M6 STMicroelectronics, ST52T440F3M6 Datasheet - Page 42

• Manufacturer Part Number: ST52T440F3M6
• Description: MCU 8-Bit ST52 CISC 8KB EPROM 5V 20-Pin SO
• Manufacturer: STMicroelectronics

Specifications of ST52T440F3M6

• Package: 20SO
• Family Name: ST52
• Maximum Speed: 20 MHz
• Ram Size: 256 Byte
• Program Memory Size: 8 KB
• Operating Supply Voltage: 5 V
• Data Bus Width: 8 Bit
• Program Memory Type: EPROM
• Number Of Programmable I/os: 13
• On-chip Adc: 6-chx12-bit
• Operating Temperature: -40 to 85 °C
• Number Of Timers: 1

ST52T400/T440/E440/T441
5 CLOCK, RESET & POWER SAVING MODE
5.1 Clock System
The ST52x400/440/441 Clock Generator module
generates the internal clock for the internal Con-
trol Unit, ALU and on-chip peripherals and is
designed to require a minimum of external compo-
nents.
The ST52x400/440/441 oscillator circuit gener-
ates an internal clock signal with the same period
and phase as at the OSCin input pin. The maxi-
mum frequency allowed is 20 MHz.
The system clock may be generated by using
either a quartz crystal, ceramic resonator (CER-
ALOC), or an external clock.
Figure 5.1 Oscillator Connections
42/94
Cl1
10pF
OSCin
CRYSTAL CLOCK
ST52X440
OSCout
Cl2
10pF
The different clock generator options connection
methods are illustrated in Oscillator Connec-
tions.When an external clock is used, it must be
connected to the pin OSCin while OSCout should
be left floating.
The crystal oscillator start-up time is a function of
many variables: crystal parameters (especially
R
ters, environment temperature, supply voltage.
It must be observed that the crystal or ceramic
lead and circuit connections must be as short as
possible. Typical values for CL1, CL2 are 10pF for
a 20 MHz crystal.
s
), oscillator load capacitance (CL), IC parame-
OSCin
CLOCK
INPUT
EXTERNAL CLOCK
ST52X440
OSCout