AT89C51IC2-RLTIL Atmel, AT89C51IC2-RLTIL Datasheet - Page 19

• Manufacturer Part Number: AT89C51IC2-RLTIL
• Description: IC 8051 MCU FLASH 32K 44VQFP
• Manufacturer: Atmel
• Series: 89Cr

Specifications of AT89C51IC2-RLTIL

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 40MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: POR, PWM, WDT
• Number Of I /o: 34
• Program Memory Size: 32KB (32K x 8)
• Program Memory Type: FLASH
• Ram Size: 1.25K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.6 V
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-TQFP, 44-VQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Data Converters: -

Design Considerations
Oscillators Control
Prescaler Divider
4301D–8051–02/08
Table 18. Overview (Continued)
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PCON.1 PCON.0
0
0
1
PwdOscA and PwdOscB signals are generated in the Clock generator and used to
control the hard blocks of oscillators A and B.
PwdOscA =’1’ stops OscA
PwdOscB =’1’ stops OscB
The following tables summarize the Operating modes:
A hardware RESET puts the prescaler divider in the following state:
–
CKS signal selects OSCA or OSCB: F
Any value between FFh down to 00h can be written by software into CKRL register
in order to divide frequency of the selected oscillator:
–
–
PCON.1
PCON.1
CKRL = FFh: F
CKRL = 00h: minimum frequency
F
F
CKRL = FFh: maximum frequency
F
F
CLK CPU
CLK CPU
CLK CPU
CLK CPU
0
1
0
0
1
0
X
1
1
= F
= F
= F
= F
OscBEn OscAEn
CLK PERIPH
CLK PERIPH
CLK PERIPH
CLK PERIPH
X
X
1
CLK CPU
OscAEn
OscBEn
X
1
1
= F
= F
= F
= F
= F
X
X
1
0
1
0
OSCA
OSCA
OSCA
OSCA
CLK PERIPH
CKS
/1020 (Standard Mode)
/510 (X2 Mode)
1
0
X
/2 (Standard Mode)
(X2 Mode)
CLK OUT
IDLE MODE A
IDLE MODE B
POWER DOWN
MODE
Selected Mode
= F
OSCA
= F
PwdOscA
PwdOscB
/2 (Standard C51 feature)
OSCA
0
1
1
0
1
1
or F
The CPU is off, OscA supplies the
peripherals, OscB can be disabled
(OscBEn = 0)
The CPU is off, OscB supplies the
peripherals, OscA can be disabled
(OscAEn = 0)
The CPU and peripherals are off,
OscA and OscB are stopped
OSCB
Comment
Power-down mode
Power-down mode
OscA stopped by
OscA stopped by
OscB stopped by
OscB stopped by
clearing OscAEn
clearing OscBEn
OscA running
OscB running
Comments
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