
29
4109LS–8051–02/08
AT8xC51SND1C
7.3.3.3
Waveforms
Figure 7-12. External IDE 16-bit Bus Cycle - Data Read Waveforms
Note:
1. D15:8 is written in DAT16H SFR.
Figure 7-13. External IDE 16-bit Bus Cycle - Data Write Waveforms
Note:
1. D15:8 is the content of DAT16H SFR.
7.4
SPI Interface
7.4.0.4
Definition of Symbols
Table 32. SPI Interface Timing Symbol Definitions
TAVDV
TLLAX
TRHDX
TRHDZ
TAVLL
TAVRL
P2
P0
RD
ALE
TLHLL
T
RLRH
Data In
TRLAZ
T
LLRL
T
RHLH
T
RLDV
D7:0
A7:0
Data In
D15:8(1)
A15:8
T
WHLH
T
AVWL
T
LLAX
T
WHQX
P2
P0
WR
ALE
T
LHLL
T
WLWH
TAVLL
T
QVWH
D7:0
Data Out
T
LLWL
A7:0
D15:8(1)
Data Out
A15:8
Signals
Conditions
C
Clock
H
High
I
Data In
L
Low
O
Data Out
V
Valid
X
No Longer Valid
Z
Floating