AT89S52-24PU Atmel, AT89S52-24PU Datasheet - Page 10
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AT89S52-24PU
Manufacturer Part Number
AT89S52-24PU
Description
IC MCU 8K FLASH 24MHZ 40-DIP
Manufacturer
Atmel
Series
89Sr
Specifications of AT89S52-24PU
Core Processor
8051
Core Size
8-Bit
Speed
24MHz
Connectivity
UART/USART
Peripherals
WDT
Number Of I /o
32
Program Memory Size
8KB (8K x 8)
Program Memory Type
FLASH
Ram Size
256 x 8
Voltage - Supply (vcc/vdd)
4 V ~ 5.5 V
Oscillator Type
Internal
Operating Temperature
-40°C ~ 85°C
Package / Case
40-DIP (0.600", 15.24mm)
Package
40PDIP
Device Core
8051
Family Name
89S
Maximum Speed
24 MHz
Operating Supply Voltage
5 V
Data Bus Width
8 Bit
Number Of Programmable I/os
32
Interface Type
UART
Number Of Timers
3
Processor Series
AT89x
Core
8051
Data Ram Size
256 B
Maximum Clock Frequency
24 MHz
Maximum Operating Temperature
+ 85 C
Mounting Style
Through Hole
3rd Party Development Tools
PK51, CA51, A51, ULINK2
Development Tools By Supplier
AT89ISP
Minimum Operating Temperature
- 40 C
Eeprom Memory
0 Bytes
Input Output
32
Interface
UART
Memory Type
Flash
Number Of Bits
8
Package Type
40-pin PDIP
Programmable Memory
8K Bytes
Timers
3-16-bit
Voltage, Range
4-5.5 V
Cpu Family
89S
Device Core Size
8b
Frequency (max)
24MHz
Total Internal Ram Size
256Byte
# I/os (max)
32
Number Of Timers - General Purpose
3
Operating Supply Voltage (typ)
5V
Operating Supply Voltage (max)
5.5V
Operating Supply Voltage (min)
4V
Instruction Set Architecture
CISC
Operating Temp Range
-40C to 85C
Operating Temperature Classification
Industrial
Mounting
Through Hole
Pin Count
40
Controller Family/series
(8051) 8052
No. Of I/o's
32
Ram Memory Size
256Byte
Cpu Speed
24MHz
No. Of Timers
3
Rohs Compliant
Yes
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Eeprom Size
-
Data Converters
-
Lead Free Status / Rohs Status
Lead free / RoHS Compliant
Other names
Q2897580
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
AT89S52-24PU
Manufacturer:
NQVATEK
Quantity:
2 140
Company:
Part Number:
AT89S52-24PU
Manufacturer:
ATM
Quantity:
4 690
Company:
Part Number:
AT89S52-24PU
Manufacturer:
ATM
Quantity:
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Part Number:
AT89S52-24PU
Manufacturer:
ATMEL/爱特梅尔
Quantity:
20 000
6. Memory Organization
6.1
6.2
7. Watchdog Timer (One-time Enabled with Reset-out)
7.1
10
Program Memory
Data Memory
Using the WDT
AT89S52
MCS-51 devices have a separate address space for Program and Data Memory. Up to 64K
bytes each of external Program and Data Memory can be addressed.
If the EA pin is connected to GND, all program fetches are directed to external memory.
On the AT89S52, if EA is connected to V
1FFFH are directed to internal memory and fetches to addresses 2000H through FFFFH are to
external memory.
The AT89S52 implements 256 bytes of on-chip RAM. The upper 128 bytes occupy a parallel
address space to the Special Function Registers. This means that the upper 128 bytes have the
same addresses as the SFR space but are physically separate from SFR space.
When an instruction accesses an internal location above address 7FH, the address mode used
in the instruction specifies whether the CPU accesses the upper 128 bytes of RAM or the SFR
space. Instructions which use direct addressing access the SFR space.
For example, the following direct addressing instruction accesses the SFR at location 0A0H
(which is P2).
Instructions that use indirect addressing access the upper 128 bytes of RAM. For example, the
following indirect addressing instruction, where R0 contains 0A0H, accesses the data byte at
address 0A0H, rather than P2 (whose address is 0A0H).
Note that stack operations are examples of indirect addressing, so the upper 128 bytes of data
RAM are available as stack space.
The WDT is intended as a recovery method in situations where the CPU may be subjected to
software upsets. The WDT consists of a 14-bit counter and the Watchdog Timer Reset
(WDTRST) SFR. The WDT is defaulted to disable from exiting reset. To enable the WDT, a user
must write 01EH and 0E1H in sequence to the WDTRST register (SFR location 0A6H). When
the WDT is enabled, it will increment every machine cycle while the oscillator is running. The
WDT timeout period is dependent on the external clock frequency. There is no way to disable
the WDT except through reset (either hardware reset or WDT overflow reset). When WDT over-
flows, it will drive an output RESET HIGH pulse at the RST pin.
To enable the WDT, a user must write 01EH and 0E1H in sequence to the WDTRST register
(SFR location 0A6H). When the WDT is enabled, the user needs to service it by writing 01EH
and 0E1H to WDTRST to avoid a WDT overflow. The 14-bit counter overflows when it reaches
16383 (3FFFH), and this will reset the device. When the WDT is enabled, it will increment every
machine cycle while the oscillator is running. This means the user must reset the WDT at least
every 16383 machine cycles. To reset the WDT the user must write 01EH and 0E1H to
WDTRST. WDTRST is a write-only register. The WDT counter cannot be read or written. When
MOV 0A0H, #data
MOV @R0, #data
CC
, program fetches to addresses 0000H through
1919C–MICRO–3/05