Chapter 5 External Bus Interface (S12XEBIV4)
MC9S12XE-Family Reference Manual , Rev. 1.19
252
Freescale Semiconductor
5.4.2.4.2
Write Access Timing
5.4.2.4.3
Read-Write-Read Access Timing
DATA[15:0] (external read)
...
?
z
z
z
z
z
...
data 0
z
...
RW
...
1
1
1
1
1
1
...
1
1
...
Table 5-15. Write Access (1 Cycle)
Access #0
Access #1
Access #2
Bus cycle ->
...
1
2
3
...
ECLK phase
...
high
low
high
low
high
low
...
ADDR[22:20] / ACC[2:0]
...
addr 0
acc 0
addr 1
acc 1
addr 2
acc 2
...
ADDR[19:16] / IQSTAT[3:0] ...
iqstat -1
iqstat 0
iqstat 1
...
ADDR[15:0] / IVD[15:0]
...
?
x
x
...
DATA[15:0] (write)
...
?
data 0
data 1
data 2
...
RW
...
0
0
1
1
1
1
...
Table 5-16. Write Access (2 Cycles)
Access #0
Access #1
Bus cycle ->
...
1
2
3
...
ECLK phase
...
high
low
high
low
high
low
...
ADDR[22:20] / ACC[2:0]
...
addr 0
acc 0
addr 0
000
addr 1
acc 1
...
ADDR[19:16] / IQSTAT[3:0] ...
iqstat-1
iqstat 0
0000
...
ADDR[15:0] / IVD[15:0]
...
?
x
x
...
DATA[15:0] (write)
...
?
data 0
x
...
RW
...
0
0
0
0
1
1
...
Table 5-17. Write Access (n–1 Cycles)
Access #0
Access #1
Bus cycle ->
...
1
2
3
...
n
...
ECLK phase
...
high
low
high
low
high
low
...
high
low
...
ADDR[22:20] / ACC[2:0]
...
addr 0
acc 0
addr 0
000
addr 0
000
...
addr 1
acc 1
...
ADDR[19:16] / IQSTAT[3:0] ...
iqstat-1
iqstat 0
0000
...
0000
...
ADDR[15:0] / IVD[15:0]
...
?
x
x
...
x
...
DATA[15:0] (write)
...
?
data 0
x
...
RW
...
0
0
0
0
0
0
...
1
1
...
Table 5-18. Interleaved Read-Write-Read Accesses (1 Cycle)
Access #0
Access #1
Access #2
Bus cycle ->
...
1
2
3
...
Table 5-14. Read Access (n–1 Cycles)
Because
of
an
order
from
the
United
States
International
Trade
Commission,
BGA-packaged
product
lines
and
part
numbers
indicated
here
currently
are
not
available
from
Freescale
for
import
or
sale
in
the
United
States
prior
to
September
2010:
S12XE
products
in
208
MAPBGA
packages