TS87C51RD2 ATMEL Corporation, TS87C51RD2 Datasheet - Page 72

• Manufacturer Part Number: TS87C51RD2
• Description: (TS8xC51Rx2) High Performance 8-bit Microcontroller
• Manufacturer: ATMEL Corporation

11.5.15
Figure 11-14. Clock Waveforms
72
MOV DEST PORT (P1, P2, P3)
(INCLUDES INT0, INT1, TO, T1)
AT/TS8xC51Rx2
Clock Waveforms
W R I T E C Y C L E
P O R T O P E R A T I O N
S E R I A L P O R T S H I F T C L O C K
E X T E R N A L P R O G R A M M E M O R Y F E T C H
P2 (EXT)
R E A D C Y C L E
MOV DEST P0
I N T E R N A L
XTAL2
CLOCK
PSEN
ALE
WR
RD
P0
P2
P0
P0
P2
TXD (MODE 0)
SAMPLED
FLOAT
DATA
STATE4
P1P2
Valid in normal clock mode. In X2 mode XTAL2 signal must be changed to XTAL2 divided by
two.
This diagram indicates when signals are clocked internally. The time it takes the signals to prop-
agate to the pins, however, ranges from 25 to 125 ns. This propagation delay is dependent on
variables such as temperature and pin loading. Propagation also varies from output to output
and component. Typically though (T
approximately 50ns. The other signals are typically 85 ns. Propagation delays are incorporated
in the AC specifications.
PCL OUT
DPL OR Rt OUT
INDICATES ADDRESS TRANSITIONS
DPL OR Rt OUT
P1P2
STATE5
P0 PINS SAMPLED
INDICATES DPH OR P2 SFR TO PCH TRANSITION
RXD SAMPLED
P1, P2, P3 PINS SAMPLED
OLD DATA
P1P2
STATE6
INDICATES DPH OR P2 SFR TO PCH TRANSITION
SAMPLED
FLOAT
DATA
NEW DATA
P1P2
STATE1
PCL OUT
A
P1P2
STATE2
=25°C fully loaded) RD and WR propagation delays are
THESE SIGNALS ARE NOT ACTIVATED DURING THE
EXECUTION OF A MOVX INSTRUCTION
DATA OUT
FLOAT
P1, P2, P3 PINS SAMPLED
P1P2
STATE3
FLOAT
SAMPLED
DATA
P1P2
PCL OUT (EVEN IF PROGRAM
MEMORY IS INTERNAL)
STATE4
PCL OUT (IF PROGRAM
MEMORY IS EXTERNAL)
PCL OUT
PCL OUT (IF PROGRAM
MEMORY IS EXTERNAL)
P1P2
STATE5
P0 PINS SAMPLED
RXD SAMPLED
4188E–8051–08/06