AT89LP52 Atmel Corporation, AT89LP52 Datasheet - Page 20

• Manufacturer Part Number: AT89LP52
• Manufacturer: Atmel Corporation

Specifications of AT89LP52

• Flash (kbytes): 8 Kbytes
• Max. Operating Frequency: 20 MHz
• Cpu: 8051-1C
• Max I/o Pins: 36
• Uart: 1
• Sram (kbytes): 0.25
• Eeprom (bytes): 256
• Self Program Memory: IAP
• Operating Voltage (vcc): 2.4 to 5.5
• Timers: 3
• Isp: SPI
• Watchdog: Yes

Table 3-3.
Notes:
20
WDIDLE
DISRTO
WS[1-0]
EXRAM
DISALE
Symbol
AUXR = 8EH
Not Bit Addressable
Bit
1. AUXR.4 and AUXR.3 function as WDIDLE and DISRTO only in Compatibility mode. In Fast mode these bits are located in
2. WS1 is only available in Fast mode. WS1 is forced to 0 in Compatibility mode.
AT89LP51/52
WDTCON.
Function
WDT Disable during Idle
halts counting in Idle mode.
Disable Reset Output
When DISRTO = 1 the reset pin is input only.
Wait State Select. Determines the number of wait states inserted into external memory accesses.
WS1
0
0
1
1
External RAM Enable. When EXRAM = 0, MOVX instructions can access the internally mapped portions of the address
space. Accesses to addresses above internally mapped memory will access external memory. Set EXRAM = 1 to
bypass the internal memory and map the entire address space to external memory.
ALE Disable. When DISALE = 0 the ALE pulse is active at 1/3 of the system clock frequency in Compatibility mode and
1/2 of the system clock frequency in Fast mode. When DISALES = 1 the ALE is inactive (high) unless an external
memory access occurs. DISALE must be set to use P4.4 as a general I/O.
AUXR
(2)
–
7
– Auxiliary Control Register
WS0
0
1
0
1
Figure 3-12. Fast Mode External Data Memory Write Cycle (WS = 00B)
–
6
(1)
Wait States
0
1
2
3
CLK
ALE
. When DISTRO = 0 the reset pin is driven to the same level as POL when the WDT resets.
WR
(1)
P0
P2
. When WDIDLE = 0 the WDT continues to count in Idle mode. When WDIDLE = 1 the WDT
–
5
P0 SFR
P2 SFR
S1
RD / WR Strobe Width
1 x t
2 x t
2 x t
3 x t
CYC
CYC
CYC
CYC
WDIDLE
(Fast); 3 x t
(Fast); 15 x t
(Fast)
(Fast)
4
DPL or Ri OUT
(1)
S2
CYC
CYC
DISRTO
WS1
(Compatibility)
(Compatibility)
3
(2)
(1)
DPH or P2 OUT
S3
WS0
2
ALE to RD / WR Setup
1 x t
1 x t
2 x t
2 x t
DATA OUT
CYC
CYC
CYC
CYC
Reset Value = xxx0 0000B
(Fast); 1.5 x t
(Fast); 1.5 x t
(Fast)
(Fast)
EXRAM
1
S4
CYC
CYC
(Compatibility)
(Compatibility)
DISALE
3709D–MICRO–12/11
P0 SFR
P2 SFR
0