AT89LP52-20AU Atmel, AT89LP52-20AU Datasheet - Page 27

• Manufacturer Part Number: AT89LP52-20AU
• Description: IC MCU 8051 8K FLASH SPI 44TQFP
• Manufacturer: Atmel
• Series: 89LPr

Specifications of AT89LP52-20AU

• 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-TQFP
• 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

Table 5-3.
3709B–MICRO–12/10
Symbol
DPU1
DPU0
DPD1
DPD0
SIGEN
DPS
AUXR1 = A2H
Not Bit Addressable
Bit
Function
Data Pointer 1 Update. When set, MOVX @DPTR and MOVC @DPTR instructions that use DPTR1 will also update
DPTR1 based on DPD1. If DPD1 = 0 the operation is post-increment and if DPD1 = 1 the operation is post-decrement.
When DPU1 = 0, DPTR1 is not updated.
Data Pointer 0 Update. When set, MOVX @DPTR and MOVC @DPTR instructions that use DPTR0 will also update
DPTR0 based on DPD0. If DPD0 = 0 the operation is post-increment and if DPD0 = 1 the operation is post-decrement.
When DPU0 = 0, DPTR0 is not updated.
Data Pointer 1 Decrement. When set, INC DPTR instructions targeted to DPTR1 will decrement DPTR1. When cleared,
INC DPTR instructions will increment DPTR1. DPD1 also determines the direction of auto-update for DPTR1 when
DPU1 = 1.
Data Pointer 0 Decrement. When set, INC DPTR instructions targeted to DPTR0 will decrement DPTR0. When cleared,
INC DPTR instructions will increment DPTR0. DPD0 also determines the direction of auto-update for DPTR0 when
DPU0 = 1.
Signature Enable. When SIGEN = 1 all MOVC @DPTR instructions and all IAP accesses will target the signature array
memory. When SIGEN = 0, all MOVC and IAP accesses target CODE memory.
Data Pointer Select. DPS selects the active data pointer for instructions that reference DPTR. When DPS = 0, DPTR will
target DPTR0 and /DPTR will target DPTR1. When DPS = 1, DPTR will target DPTR1 and /DPTR will target DPTR0.
AUXR1
DPU1
7
– Data Pointer Configuration Register
Table 5-2.
The data pointer update bits, DPU1 and DPU0, allow MOVX @DPTR and MOVC @DPTR
instructions to update the selected data pointer automatically in a post-increment or post-decre-
ment fashion. The direction of update depends on the DPD1 and DPD0 bits as shown in
5-4. These bits can be used to make block copy routines more efficient.
Table 5-4.
DPU0
DPD1
DPD1
0
0
1
1
0
0
1
1
6
DPD0
DPD0
Data Pointer Decrement Behavior
Data Pointer Auto-Update
0
1
0
1
0
1
0
1
DPD1
5
DEC DPTR0
DEC DPTR0
INC DPTR0
INC DPTR0
INC DPTR
DPTR0++
DPTR0++
DPTR0--
DPTR0--
DPTR
DPD0
Update Operation for MOVX and MOVC (DPU1 = 1 & DPU0 = 1)
4
Equivalent Operation for INC DPTR and INC /DPTR
DPS = 0
DPS = 0
SIGEN
DEC DPTR1
DEC DPTR1
INC DPTR1
INC DPTR1
INC /DPTR
3
DPTR1++
DPTR1++
DPTR1--
DPTR1--
AT89LP51/52 - Preliminary
/DPTR
0
2
DEC DPTR1
DEC DPTR1
INC DPTR1
INC DPTR1
INC DPTR
DPTR1++
DPTR1++
DPTR1--
DPTR1--
DPTR
Reset Value = 0000 00X0B
–
1
DPS = 1
DPS = 1
DEC DPTR0
DEC DPTR0
INC DPTR0
INC DPTR0
INC /DPTR
DPTR0++
DPTR0++
DPTR0--
DPTR0--
DPS
/DPTR
0
Table
27