AT89LS53-12JI Atmel, AT89LS53-12JI Datasheet - Page 7

• Manufacturer Part Number: AT89LS53-12JI
• Description: IC 8051 MCU FLASH 12K 44PLCC
• Manufacturer: Atmel
• Series: 89LSr

Specifications of AT89LS53-12JI

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 12MHz
• Connectivity: SPI, UART/USART
• Peripherals: POR, WDT
• Number Of I /o: 32
• Program Memory Size: 12KB (12K x 8)
• Program Memory Type: FLASH
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 6 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-PLCC
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Data Converters: -
• Other names: AT89LS5312JI

Dual Data Pointer Registers To facilitate accessing exter-
nal data memory, two banks of 16 bit Data Pointer Regis-
ters are provided: DP0 at SFR address locations 82H-83H
and DP1 at 84H-85H. Bit DPS = 0 in SFR WCON selects
DP0 and DPS = 1 selects DP1. The user should always ini-
talize the DPS bit to the appropriate value before accessing
the respective Data Pointer register.
Table 3. WCON—Watchdog Control Register
0851C–MICRO–3/06
WCON Address = 96H
Symbol
PS2
PS1
PS0
DPS
WDTRST
WDTEN
Bit
PS2
7
Function
Prescaler Bits for the Watchdog Timer. When all three bits are set to “0”, the watchdog timer has a nominal
period of 16 ms. When all three bits are set to “1”, the nominal period is 2048 ms.
Data Pointer Register Select. DPS = 0 selects the first bank of Data Pointer Register, DP0, and DPS = 1
selects the second bank, DP1
Watchdog Timer Reset. Each time this bit is set to “1” by user software, a pulse is generated to reset the
watchdog timer. The WDTRST bit is then automatically reset to “0” in the next instruction cycle. The
WDTRST bit is Write-Only.
Watchdog Timer Enable Bit. WDTEN = 1 enables the watchdog timer and WDTEN = 0 disables the
watchdog timer.
PS1
6
PS0
5
reserved
4
reserved
3
Power Off Flag The Power Off Flag (POF) is located at
bit_4 (PCON.4) in the PCON SFR. POF is set to “1” during
power up. It can be set and reset under software control
and is not affected by RESET.
DPS
2
WDTRST
1
Reset Value = 0000 0010B
AT89LS53
WDTEN
0
7