AT89LP52-20JU Atmel, AT89LP52-20JU Datasheet - Page 24
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AT89LP52-20JU
Manufacturer Part Number
AT89LP52-20JU
Description
IC MCU 8051 8K FLASH SPI 44PLCC
Manufacturer
Atmel
Series
89LPr
Datasheet
1.AT89LP52-20MU.pdf
(113 pages)
Specifications of AT89LP52-20JU
Core Processor
8051
Core Size
8-Bit
Speed
20MHz
Connectivity
EBI/EMI, I²C, SPI, UART/USART
Peripherals
Brown-out Detect/Reset, POR, PWM, WDT
Number Of I /o
36
Program Memory Size
8KB (8K x 8)
Program Memory Type
FLASH
Ram Size
256 x 8
Voltage - Supply (vcc/vdd)
2.4 V ~ 5.5 V
Oscillator Type
Internal
Operating Temperature
-40°C ~ 85°C
Package / Case
44-LCC (J-Lead)
Processor Series
AT89x
Core
8051
Data Bus Width
8 bit
Data Ram Size
256 B
Interface Type
Serial
Maximum Clock Frequency
20 MHz
Number Of Programmable I/os
36
Number Of Timers
3
Operating Supply Voltage
2.7 V to 5.5 V
Maximum Operating Temperature
+ 85 C
Mounting Style
SMD/SMT
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Eeprom Size
-
Data Converters
-
Lead Free Status / Rohs Status
Details
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
AT89LP52-20JU
Manufacturer:
Atmel
Quantity:
110
5. Enhanced CPU
5.1
24
Fast Mode
AT89LP51/52 - Preliminary
The AT89LP51/52 uses an enhanced 8051 CPU that runs at 6 to 12 times the speed of standard
8051 devices (or 3 to 6 times the speed of X2 8051 devices). The increase in performance is
due to two factors. First, the CPU fetches one instruction byte from the code memory every clock
cycle. Second, the CPU uses a simple two-stage pipeline to fetch and execute instructions in
parallel. This basic pipelining concept allows the CPU to obtain up to 1 MIPS per MHz. The
AT89LP51/52 also has a Compatibility mode that preserves the 12-clock machine cycle of stan-
dard 8051s like the AT89S51/52.
Fast (Single-Cycle) mode must be enabled by clearing the Compatibility User Fuse. (See
Configuration Fuses” on page
clock cycle. The 8051 instruction set allows for instructions of variable length from 1 to 3 bytes.
In a single-clock-per-byte-fetch system this means each instruction takes at least as many
clocks as it has bytes to execute. The majority of instructions in the AT89LP51/52 follow this
rule: the instruction execution time in system clock cycles equals the number of bytes per
instruction, with a few exceptions. Branches and Calls require an additional cycle to compute the
target address and some other complex instructions require multiple cycles.
Summary” on page 75.
Example of Fast mode instructions are shown in
take three times as long to execute if they are fetched from external program memory.
Figure 5-1.
Instruction Execution Sequences in Fast Mode
for more detailed information on individual instructions.
(A) 1-byte, 1-cycle instruction, e.g. INC A
(B) 2-byte, 2-cycle instruction, e.g. ADD A, #data
(C) 1-byte, 2-cycle instruction, e.g. INC DPTR
(D) MOVX (1-byte, 4-cycle)
CLK
86.) In this mode one instruction byte is fetched every system
S1
S1
S1
S1
ACCESS EXTERNAL
ADDR
READ OPERAND
READ NEXT
OPCODE
S2
S2
S2
MEMORY
READ NEXT OPCODE
READ NEXT OPCODE
S3
Figure
DATA
S4
5-1. Note that Fast mode instructions
READ NEXT
OPCODE
See “Instruction Set
3709B–MICRO–12/10
“User