128
SAM7S Series [DATASHEET]
6175M–ATARM–26-Oct-12
20.2.4.2
Read Handshaking
For details on the read handshaking sequence, refer to Figure 20-5, Figure 20-6 and Table 20-5.
Figure 20-5.
SAM7S542/256/128/321/161 Parallel Programming Timing, Read Sequence
Figure 20-6. SAM7S32/16 Parallel Programming Timing, Read Sequence
Table 20-4.
Write Handshake
Step
Programmer Action
Device Action
Data I/O
1
Sets MODE and DATA signals
Waits for NCMD low
Input
2
Clears NCMD signal
Latches MODE and DATA
Input
3
Waits for RDY low
Clears RDY signal
Input
4
Releases MODE and DATA signals
Executes command and polls NCMD high
Input
5
Sets NCMD signal
Executes command and polls NCMD high
Input
6
Waits for RDY high
Sets RDY
Input
NCMD
RDY
NOE
NVALID
DATA[15:0]
MODE[3:0]
1
2
3
4
5
6
7
9
8
ADDR
Adress IN
Z
Data OUT
10
11
XIN
12
13
NCMD
RDY
NOE
NVALID
DATA[7:0]
MODE[3:0]
1
2
3
4
5
6
7
9
8
ADDR
Adress IN
Z
Data OUT
10
11
XIN
12
13