AT89LP51ED2-20AAU Atmel, AT89LP51ED2-20AAU Datasheet - Page 40
AT89LP51ED2-20AAU
Manufacturer Part Number
AT89LP51ED2-20AAU
Description
8-bit Microcontrollers - MCU 64KB 20MHz 2.4V-5.5V
Manufacturer
Atmel
Datasheet
1.AT89LP51ED2-20AAU.pdf
(254 pages)
Specifications of AT89LP51ED2-20AAU
Rohs
yes
Core
8051
Processor Series
AT89x
Data Bus Width
8 bit
Maximum Clock Frequency
20 MHz
Program Memory Size
64 KB
Data Ram Size
256 B
On-chip Adc
Yes
Operating Supply Voltage
2.4 V to 5.5 V
Operating Temperature Range
- 40 C to + 85 C
Package / Case
LQFP-44
Mounting Style
SMD/SMT
Data Rom Size
4 KB
Interface Type
2-Wire, SPI, UART
Number Of Programmable I/os
36
Number Of Timers
3
Program Memory Type
Flash
Factory Pack Quantity
160
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
- Current page: 40 of 254
- Download datasheet (7Mb)
5.4.2
5.4.2.1
5.4.2.2
40
AT89LP51RD2/ED2/ID2 Preliminary
Data Pointer Operating Modes
DPTR Redirect
Index Disable
The Dual Data Pointers on the AT89LP51RD2/ED2/ID2 include three additional operating
modes that affect data pointer based instructions. These modes are controlled by bits in DSPR.
Note that these bits in DSPR should be cleared to zero, disabling these modes, before any calls
are made to the Flash API.Care must also be taken when interrupt routines use data pointers to
ensure that correct operation is saved/restored correctly.
The Data Pointer Redirect to B bit, DPRB (DSPR.0), allows MOVX and MOVC instructions to
use the B register as the data source/destination when the instruction references DPTR1 as
shown in
multiple operands from different RAM locations.
Table 5-8.
The MOVC Index Disable bit, MVCD (DSPR.1), disables the indexed addressing mode of the
MOVC A, @A+DPTR instruction. When MVCD = 1, the MOVC instruction functions as
MOVC A, @DPTR with no indexing as shown in
routines that must fetch multiple operands from program memory. DPRB can change the MOVC
destination register from ACC to B, but has no effect on the MOVC index register.
Table 5-9.
DPRB
MVCD
0
0
1
1
0
0
1
1
Table 5-8
DPRB
DPS
MOVX @DPTR Operating Modes
0
1
0
1
MOVC @DPTR Operating Modes
0
1
0
1
and
A, @A+DPTR0
A, @A+DPTR0
A, @DPTR0
A, @DPTR1
A, @DPTR0
B, @DPTR1
A, @DPTR0
A, @DPTR0
Table
MOVX
MOVX
MOVX
MOVX
MOVC
MOVC
MOVC
MOVC
DPTR
DPTR
MOVX A, @DPTR
5-9. DPRB can improve the efficiency of routines that must fetch
DPS = 0
Equivalent Operation for MOVC A, @A+DPTR
A, @A+DPTR1
B, @A+DPTR1
Equivalent Operation for MOVX
A, @DPTR0
A, @DPTR1
A, @DPTR0
B, @DPTR1
A, @DPTR1
B, @DPTR1
/DPTR
/DPTR
MOVX
MOVX
MOVX
MOVX
MOVC
MOVC
MOVC
MOVC
Table
5-9. MVCD can improve the efficiency of
A, @A+DPTR1
B, @A+DPTR1
@DPTR0, A
@DPTR1, A
@DPTR0, A
@DPTR1, B
A, @DPTR1
B, @DPTR1
MOVC
MOVC
MOVC
MOVC
MOVX
MOVX
MOVX
MOVX
DPTR
DPTR
MOVX @DPTR, A
DPS = 1
A, @A+DPTR0
A, @A+DPTR0
@DPTR1, A
@DPTR0, A
@DPTR1, B
@DPTR0, A
A, @DPTR0
A, @DPTR0
3714A–MICRO–7/11
/DPTR
MOVX
MOVX
MOVX
MOVX
/DPTR
MOVC
MOVC
MOVC
MOVC
Related parts for AT89LP51ED2-20AAU
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
Part Number:
Description:
DEV KIT FOR AVR/AVR32
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
INTERVAL AND WIPE/WASH WIPER CONTROL IC WITH DELAY
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
Low-Voltage Voice-Switched IC for Hands-Free Operation
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
MONOLITHIC INTEGRATED FEATUREPHONE CIRCUIT
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
AM-FM Receiver IC U4255BM-M
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
Monolithic Integrated Feature Phone Circuit
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
Multistandard Video-IF and Quasi Parallel Sound Processing
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
High-performance EE PLD
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
8-bit Flash Microcontroller
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
2-Wire Serial EEPROM
Manufacturer:
ATMEL Corporation
Datasheet: