AT89C51CC03CA-RLTUM Atmel, AT89C51CC03CA-RLTUM Datasheet - Page 17

• Manufacturer Part Number: AT89C51CC03CA-RLTUM
• Description: IC 8051 MCU 64K FLASH 44-VQFP
• Manufacturer: Atmel
• Series: AT89C CANr

Specifications of AT89C51CC03CA-RLTUM

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 40MHz
• Connectivity: CAN, UART/USART
• Peripherals: POR, PWM, WDT
• Number Of I /o: 36
• Program Memory Size: 64KB (64K x 8)
• Program Memory Type: FLASH
• Eeprom Size: 2K x 8
• Ram Size: 2.25K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-TQFP, 44-VQFP
• Processor Series: AT89x
• Core: 8051
• Data Bus Width: 8 bit
• Data Ram Size: 2304 B
• Interface Type: UART, SPI
• Maximum Clock Frequency: 60 MHz
• Number Of Programmable I/os: 36
• Number Of Timers: 2
• Operating Supply Voltage: 3 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: PK51, CA51, A51, ULINK2
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 8 Channel
• Package: 44VQFP
• Device Core: 8051
• Family Name: AT89
• Maximum Speed: 60 MHz
• For Use With: AT89OCD-01 - USB EMULATOR FOR AT8XC51 MCU
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Clock
Description
4182O–CAN–09/08
The AT89C51CC03 core needs only 6 clock periods per machine cycle. This feature,
called”X2”, provides the following advantages:
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•
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In order to keep the original C51 compatibility, a divider-by-2 is inserted between the
XTAL1 signal and the main clock input of the core (phase generator). This divider may
be disabled by the software.
An extra feature is available to start after Reset in the X2 mode. This feature can be
enabled by a bit X2B in the Hardware Security Byte. This bit is described in the section
"In-System Programming".
The X2 bit in the CKCON register (see Table 2) allows switching from 12 clock cycles
per instruction to 6 clock cycles and vice versa. At reset, the standard speed is activated
(STD mode).
Setting this bit activates the X2 feature (X2 mode) for the CPU Clock only (see Figure
5.).
The Timers 0, 1 and 2, Uart, PCA, WatchDog or CAN switch in X2 mode only if the cor-
responding bit is cleared in the CKCON register.
The clock for the whole circuit and peripheral is first divided by two before being used by
the CPU core and peripherals. This allows any cyclic ratio to be accepted on the XTAL1
input. In X2 mode, as this divider is bypassed, the signals on XTAL1 must have a cyclic
ratio between 40 to 60%. Figure 5. shows the clock generation block diagram. The X2
bit is validated on the XTAL1÷2 rising edge to avoid glitches when switching from the X2
to the STD mode. Figure 6 shows the mode switching waveforms.
Divides frequency crystals by 2 (cheaper crystals) while keeping the same CPU
power.
Saves power consumption while keeping the same CPU power (oscillator power
saving).
Saves power consumption by dividing dynamic operating frequency by 2 in
operating and idle modes.
Increases CPU power by 2 while keeping the same crystal frequency.
AT89C51CC03
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