AT89C51RD2-RLRUM Atmel, AT89C51RD2-RLRUM Datasheet - Page 18

• Manufacturer Part Number: AT89C51RD2-RLRUM
• Description: IC MCU FLASH 8051 EEP 64K 44VQFP
• Manufacturer: Atmel
• Series: 89Cr

Specifications of AT89C51RD2-RLRUM

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 60MHz
• Connectivity: SPI, UART/USART
• Peripherals: POR, PWM, WDT
• Number Of I /o: 34
• Program Memory Size: 64KB (64K x 8)
• Program Memory Type: FLASH
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• 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: 2 KB
• Interface Type: UART, SPI
• Maximum Clock Frequency: 60 MHz
• Number Of Programmable I/os: 32
• Number Of Timers: 3
• Operating Supply Voltage: 2.7 V to 5.5 V
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: PK51, CA51, A51, ULINK2
• For Use With: AT89STK-11 - KIT STARTER FOR AT89C51RX2
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Data Converters: -
• Lead Free Status / Rohs Status: Details
• Other names: AT89C51RD2-RLRUMTR

Figure 7-2.
18
AT89C51RD2/ED2
XTAL1
XTAL1:2
X2 Bit
CPU Clock
Mode Switching Waveforms
STD Mode
Figure 7-1.
The X2 bit in the CKCON0 register (see Table 7-1) allows a switch from 12 clock periods per
instruction to 6 clock periods and vice versa. At reset, the speed is set according to X2 bit of
Hardware Security Byte (HSB). By default, Standard mode is active. Setting the X2 bit activates
the X2 feature (X2 mode).
The T0X2, T1X2, T2X2, UartX2, PcaX2, and WdX2 bits in the CKCON0 register
SPIX2 bit in the CKCON1 register (see Table 7-2) allows a switch from standard peripheral
speed (12 clock periods per peripheral clock cycle) to fast peripheral speed (6 clock periods per
peripheral clock cycle). These bits are active only in X2 mode.
Table 7-1.
CKCON0 - Clock Control Register (8Fh)
Number
Bit
7
7
6
-
XTAL1
Mnemonic
Reserved
Clock Generation Diagram
CKCON0 Register
WDX2
WDX2
Bit
6
FXTAL
Description
The values for this bit are indeterminite. Do not set this bit.
Watchdog Clock
(This control bit is validated when the CPU clock X2 is set; when X2 is low, this bit has no
effect).
Cleared to select 6 clock periods per peripheral clock cycle.
Set to select 12 clock periods per peripheral clock cycle.
PCAX2
5
2
F
XTAL1:2
X2 Mode
OSC
SIX2
4
CKCON0
X2
0
1
F
OSC
T2X2
3
8-bit Prescaler
CKRL
T1X2
2
STD Mode
T0X2
1
(Table
4235K–8051–05/08
F
F
CLK CPU
CLK PERIPH
7-1) and
X2
0