AT89LP216 Atmel Corporation, AT89LP216 Datasheet - Page 12

• Manufacturer Part Number: AT89LP216
• Manufacturer: Atmel Corporation

Specifications of AT89LP216

• Flash (kbytes): 2 Kbytes
• Max. Operating Frequency: 20 MHz
• Cpu: 8051-1C
• Max I/o Pins: 14
• Spi: 1
• Uart: 1
• Sram (kbytes): 0.125
• Operating Voltage (vcc): 2.4 to 5.5
• Timers: 2
• Isp: SPI/OCD
• Watchdog: Yes

9.2
9.3
9.4
12
External Clock Source
Internal RC Oscillator
System Clock Out
AT89LP216
The external clock option disables the oscillator amplifier and allows XTAL1 to be driven directly
by the clock source as shown in
or configured to output a divided version of the system clock.
Figure 9-2.
The AT89LP216 has an internal RC oscillator tuned to 8.0 MHz ±1.0% at 5.0V and 25⋅ C. When
enabled as the clock source, XTAL1 and XTAL2 may be used as P3.2 and P3.3, respectively.
The XTAL2 may also be configured to output a divided version of the system clock. The fre-
quency of the oscillator may be adjusted by changing the RC Adjust Fuses.
Configuration Fuses” on page
of the Atmel Signature.
When the AT89LP216 is configured to use either an external clock or the internal RC oscillator,
a divided version of the system clock may be output on XTAL2 (P3.3). The Clock Out feature is
enabled by setting the COE bit in CLKREG. The two CDV bits determine the clock divide ratio.
For example, setting COE = “1” and CDIV = “00” when using the internal oscillator will result in a
4.0 MHz clock output on P3.3. P3.3 must be configured as an output in order to use the clock out
feature.
External Clock Drive Configuration
71.) A copy of the initial factory setting is stored at location 0007h
Figure
OSCILLATOR
NC, GPIO, or
EXTERNAL
CLKOUT
SIGNAL
9-2. XTAL2 may be left unconnected, used as P3.3 I/O,
XTAL2 (P3.3)
XTAL1 (P3.2)
GND
3621E–MICRO–11/10
(See “User