AT89LP6440 Atmel Corporation, AT89LP6440 Datasheet - Page 20

• Manufacturer Part Number: AT89LP6440
• Manufacturer: Atmel Corporation

Specifications of AT89LP6440

• Flash (kbytes): 64 Kbytes
• Max. Operating Frequency: 20 MHz
• Cpu: 8051-1C
• Max I/o Pins: 38
• Spi: 1
• Twi (i2c): 1
• Uart: 1
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 153.8
• Sram (kbytes): 4.25
• Eeprom (bytes): 8192
• Self Program Memory: IAP
• Operating Voltage (vcc): 2.4 to 3.6
• Timers: 3
• Isp: SPI/OCD
• Watchdog: Yes

3.4
20
Extended Stack
AT89LP3240/6440
Figure 3-11. MOVX with One Wait State (WS = 01B)
Figure 3-12. MOVX with Two Wait States (WS = 10B)
Figure 3-13. MOVX with Three Wait States (WS = 11B)
The AT89LP3240/6440 provides an extended stack space for applications requiring additional
stack memory. By default the stack is located in the 256-byte IDATA space of internal data
memory. The IDATA stack is referenced solely by the 8-bit Stack Pointer (SP: 81H). Setting the
XSTK bit in AUXR enables the extended stack. The extended stack resides in the EDATA space
for up to 4KB of stack memory. The extended stack is referenced by a 12-bit pointer formed from
SP and the four LSBs of the Extended Stack Pointer (SPX: 9EH) as shown in
shared between both stacks. Note that the standard IDATA stack will not overflow to the EDATA
stack or vice versa. The stack and extended stack are mutually exclusive and SPX is ignored
when XTSK = 0. An application choosing to switch between stacks by toggling XSTK must main-
CLK
CLK
CLK
ALE
ALE
ALE
WR
WR
WR
RD
RD
RD
P2
P0
P0
P2
P0
P0
P2
P0
P0
P2 SFR
P0 SFR
P0 SFR
P2 SFR
P0 SFR
P0 SFR
P2 SFR
P0 SFR
P0 SFR
S1
S1
S1
DPL OUT
DPL OUT
DPL OUT
DPL OUT
DPL OUT
DPL OUT
S2
S2
S2
S3
S3
S3
DPH or P2 OUT
DPH or P2 OUT
DATA OUT
FLOAT
W1
W1
W1
DPH or P2 OUT
DATA OUT
FLOAT
DATA OUT
FLOAT
W2
W2
S4
P2 SFR
P0 SFR
P0 SFR
W3
S4
P2 SFR
P0 SFR
P0 SFR
S4
P2 SFR
P0 SFR
P0 SFR
Figure
3706C–MICRO–2/11
3-14. SP is