AT89C51CC03U-S3SIM ATMEL [ATMEL Corporation], AT89C51CC03U-S3SIM Datasheet - Page 20

• Manufacturer Part Number: AT89C51CC03U-S3SIM
• Description: Enhanced 8-bit MCU with CAN Controller and Flash Memory
• Manufacturer: ATMEL [ATMEL Corporation]

Figure 6. Mode Switching Waveforms
Note:
20
In order to prevent any incorrect operation while operating in the X2 mode, users must be aware that all peripherals using the
clock frequency as a time reference (UART, timers...) will have their time reference divided by two. For example a free running
timer generating an interrupt every 20 ms will then generate an interrupt every 10 ms. A UART with a 4800 baud rate will have
a 9600 baud rate.
AT89C51CC03
XTAL1
XTAL1/2
X2 bit
CPU clock
STD Mode
X2 Mode
STD Mode
4182I–CAN–06/05