AT83C5135 Atmel Corporation, AT83C5135 Datasheet - Page 13

• Manufacturer Part Number: AT83C5135
• Manufacturer: Atmel Corporation

Specifications of AT83C5135

• Max. Operating Frequency: 32 MHz
• Cpu: 8051-12C
• Max I/o Pins: 34
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 1
• Twi (i2c): 1
• Uart: 1
• Sram (kbytes): 1.25
• Eeprom (bytes): 512
• Operating Voltage (vcc): 2.7 to 3.6
• Timers: 4
• Mask Rom (kbytes): 16
• Watchdog: Yes

6. Clock Controller
6.1
Figure 6-1.
6.2
7683C–USB–11/07
Introduction
Oscillator
X1
X2
Oscillator Block Diagram
PLLCON.2
EXT48
The AT83C5134/35/36 clock controller is based on an on-chip oscillator feeding an on-chip
Phase Lock Loop (PLL). All the internal clocks to the peripherals and CPU core are generated
by this controller.
The AT83C5134/35/36 X1 and X2 pins are the input and the output of a single-stage on-chip
inverter (see Figure 6-1) that can be configured with off-chip components as a Pierce oscillator
(see Figure 6-2). Value of capacitors and crystal characteristics are detailed in the section “DC
Characteristics”.
The X1 pin can also be used as input for an external 48 MHz clock.
The clock controller outputs three different clocks as shown in Figure 6-1:
These clocks are enabled or disabled depending on the power reduction mode as detailed in
Section “Power Management”, page 135.
Two clock sources are available for CPU:
PCON.1
• a clock for the CPU core
• a clock for the peripherals which is used to generate the Timers, PCA, WD, and Port
• a clock for the USB controller
• Crystal oscillator on X1 and X2 pins: Up to 32 MHz
• External 48 MHz clock on X1 pin
PD
sampling clocks
PLL
0
1
÷
2
CKCON.0
X2
0
1
PCON.0
AT83C5134/35/36
IDL
USB
Clock
Peripheral
Clock
CPU Core
Clock
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