AT89S8253-24AU Atmel, AT89S8253-24AU Datasheet - Page 35

• Manufacturer Part Number: AT89S8253-24AU
• Description: IC MCU 12K FLASH 24MHZ 44-TQFP
• Manufacturer: Atmel
• Series: 89Sr

Specifications of AT89S8253-24AU

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 24MHz
• Connectivity: SPI, UART/USART
• Peripherals: POR, WDT
• Number Of I /o: 32
• Program Memory Size: 12KB (12K x 8)
• Program Memory Type: FLASH
• Eeprom Size: 2K x 8
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Oscillator Type: Internal
• 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: 256 B
• Interface Type: SPI/UART
• Maximum Clock Frequency: 24 MHz
• Number Of Programmable I/os: 32
• Number Of Timers: 3
• Operating Supply Voltage: 2.7 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: PK51, CA51, A51, ULINK2
• Development Tools By Supplier: AT89ISP
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Data Converters: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

17. Idle Mode
3286P–MICRO–3/10
Figure 16-5. Ceramic Resonator Clock Source (B)
To drive the device from an external clock source, XTAL2 should be left unconnected while
XTAL1 is driven, as shown in
Figure 16-6. External Clock Drive Configuration
In idle mode, the CPU puts itself to sleep while all the on-chip peripherals remain active. This
mode is invoked by software. The content of the on-chip RAM and all the special functions regis-
ters remain unchanged during this mode. The idle mode can be terminated by any enabled
interrupt or by a hardware reset.
Note that when idle mode is terminated by a hardware reset, the device normally resumes pro-
gram execution from where it left off, up to two machine cycles before the internal reset
algorithm takes control. On-chip hardware inhibits access to internal RAM in this event, but
access to the port pins is not inhibited. To eliminate the possibility of an unexpected write to a
port pin when idle mode is terminated by a reset, the instruction following the one that invokes
idle mode should not write to a port pin or to external memory.
7
6
5
4
3
2
1
0
0
4
Ceramic Resonator Clock Input
Figure
8
16-6.
Frequency (MHz)
12
16
20
AT89S8253
C2=0pF
C2=5pF
C2=10pF
R1=4MΩ
24
35