AT89C5122 ATMEL [ATMEL Corporation], AT89C5122 Datasheet - Page 199

• Manufacturer Part Number: AT89C5122
• Description: MICROCONTROLLER WITH USB AND SMART CARD READER INTERFACES
• Manufacturer: ATMEL [ATMEL Corporation]

Float Waveforms
Clock Waveforms
4202D–SCR–06/05
EXTERNAL PROGRAM MEMORY FETCH
READ CYCLE
WRITE CYCLE
PORT OPERATION
SERIAL PORT SHIFT CLOCK
MOV PORT SRC
INTERNAL
MOV DEST PORT (P1. P2. P3)
(INCLUDES INTO. INT1. TO T1)
MOV DEST P0
P2 (EXT)
TXD (MODE 0)
CLOCK
XTAL2
PSEN
ALE
WR
RD
P0
P0
P2
P0
P2
SAMPLED
DATA
STATE4
P1
FLOAT
For timing purposes as port pin is no longer floating when a 100 mV change from load
voltage occurs and begins to float when a 100 mV change from the loaded V
occurs. I
Valid in normal clock mode. In X2 mode XTAL2 must be changed to XTAL2/2.
P2
OL
STATE5
P1
PCL OUT
INDICATES ADDRESS TRANSITIONS
DPL OR Rt OUT
DPL OR Rt OUT
P0 PINS SAMPLED
/I
OH
P2
≥ ± 20 mA.
P1, P2, P3 PINS SAMPLED
RXD SAMPLED
INDICATES DPH OR P2 SFR TO PCH TRANSITION
INDICATES DPH OR P2 SFR TO PCH TRANSITION
V
V
STATE6
P1
OLD DATA NEW DATA
OH
OL
+ 0.1 V
- 0.1 V
P2
FLOAT
SAMPLED
DATA
STATE1
P1
FLOAT
V
LOAD
P2
STATE2
P1
PCL OUT
THESE SIGNALS ARE NOT ACTIVATED DURING THE
EXECUTION OF A MOVX INSTRUCTION
DATA OUT
FLOAT
P2
SAMPLED
DATA
STATE3
P1
V
V
LOAD
LOAD
P2
FLOAT
P1, P2, P3 PINS SAMPLED
P0 PINS SAMPLED
+ 0.1 V
- 0.1 V
SAMPLED
DATA
STATE4
P1
PCL OUT (EVEN IF PROGRAM
MEMORY IS INTERNAL)
P2
RXD SAMPLED
MEMORY IS EXTERNAL)
PCL OUT (IF PROGRAM
PCL OUT (IF PROGRAM
MEMORY IS EXTERNAL
STATE5
P1
PCL OUT
P2
OH
/V
OL
level
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