AT89C5122D-RDRUM Atmel, AT89C5122D-RDRUM Datasheet - Page 44

• Manufacturer Part Number: AT89C5122D-RDRUM
• Description: IC 8051 MCU 32K CRAM USB 64-VQFP
• Manufacturer: Atmel
• Series: 89Cr

Specifications of AT89C5122D-RDRUM

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 48MHz
• Connectivity: SmartCard, SPI, UART/USART, USB
• Peripherals: LED, POR, WDT
• Number Of I /o: 46
• Program Memory Size: 32KB (32K x 8)
• Program Memory Type: FLASH
• Ram Size: 768 x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-TQFP, 64-VQFP
• For Use With: AT89OCD-01 - USB EMULATOR FOR AT8XC51 MCUAT89STK-10 - KIT EVAL APPL MASS STORAGEAT89STK-03 - KIT STARTER FOR MCU AT8XC5122/23
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Data Converters: -
• Other names: AT89C5122D-RDRUMTR

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AT83R5122, AT8xC5122/23
Figure 20. X1 mode
When the X1 mode is selected, the CPU and Peripherals work at 8Mhz / X1
Figure 21. X2 mode
When the X2 mode is selected, the CPU works at 8 MHz / X2. The Peripherals can work
at 8 MHz / X2 or 8 MHz / X1.
When the PR1 prescaler is different from 1/2, the usual X1 mode can not be defined. In
this case, it is necessary to define a X1 or X2 equivalent mode from equivalent clock
circuits.
Example : PR1=1/8, X2=0.
In this configuration, the CPU works at 1 MHz. This frequency could also be obtained by
an equivalent clock circuit where the on-chip oscillator would run at 2 MHz in X1 mode
or at 1 MHz in X2 mode. So we can say that the CPU works at 2 MHz / X1 or 1MHz / X2.
As the X2 bit is cleared in CKCON0 register, we have F
Crystal
Crystal
8 MHz
8 MHz
Internal Prescaler
PR1 prescaler
1/2
1/2
CPU frequency
Peripheral frequency
CPU frequency (X2 Mode)
Peripheral frequency (X2 mode)
Peripheral frequency (X1 mode)
4 MHz
4 MHz
8 MHz
8 MHz
4 MHz
CK_IDLE
= F
CK_PERIPH
4202F–SCR–07/2008
.