DATA SHEET
MAS 35x9F
3.3.2.4. Read Memory (Codes C
and D
)
hex
3.3.2.6. Write Memory
(Codes E and F
hex
)
hex
hex
The MAS 35x9F has 2 memory areas of 2048 words
denoted D0 and D1. The memory areas D0 and D1
The memory areas D0 and D1 can be written by using
the codes E and F , respectively.
can be written by using the codes C
respectively.
and D
,
hex
hex
hex
hex
S
DW
W
A
data_write
A
e,0
A
A
A
A
0,0
W
W
W
W
A
A
A
A
1) send command (Read D0)
n3,n2
a3,a2
d3,d2
n1,n0
a1,a0
d1,d0
S
DW
W
A
data_write
A
c,0
A
A
A
0,0
W
W
W
A
A
n3,n2
a3,a2
n1,n0
a1,a0
x,x
x,x
A
A
x,d4
W
A
A
P
....repeat for n data values....
2) get register value
x,d4
W
A
d3,d2
A
d1,d0
W
A
P
S
DW
x,x
W
A
A
data_read
A
A
S
DR
W
A
x,d4
W
d3,d2
A
d1,d0
W
W
A
N
With the Write D0/D1 Memory command n 20-bit
memory cells in D0 can be initialized with new data.
....repeat for n data values....
x,x
A
x,d4
W
A
d3,d2
A
d1,d0
P
Example: Write 80234
I C protocol:
to D1:456 has the following
hex
2
The Read D0 Memory command gives the controller
access to all 20 bits of the D0/D1 memory cells. The
telegram to read 3 words starting at location D1:100 is
<3a 68 f0 00
00 01
write D1 memory
1 word to write
start address
04 56
<DW 68 d0 00 00 03 01 00>
<DW 69 <DR xx xd dd dd
xx xd dd dd xx xd dd dd >
00 08
value = 80234
hex
02 34>
3.3.2.7. Short Write Memory
(Codes E4 and F4
3.3.2.5. Short Read Memory
)
hex
hex
(Codes C4
and D4
)
hex
hex
S
DW
W
A
data_write
A
A
A
A
e,4
A
A
A
A
0,0
W
W
W
W
A
A
A
A
Because most cells in the user interface are only 16
bits wide, it is faster and more convenient to access
the memory locations with a special 16-bit mode for
reading:
n3,n2
a3,a2
d3,d2
n1,n0
a1,a0
d1,d0
....repeat for n data values....
1) send command (e.g. Short Read D0)
A
d3,d2
A
d1,d0
W
A
P
S
DW
W
A
data_write
A
c,4
A
A
A
0,0
W
W
W
A
A
A
n3,n2
a3,a2
n1,n0
a1,a0
For faster access only the lower 16 bits of each mem-
ory cell are written. The 4 MSBs of the cell are cleared.
P
The command uses the same codes E
and F
for
2) get register value
hex
hex
D0/D1 as for the 20-bit command but followed by a 4
rather than a 0.
S
DW
W
A
data_read
A
S
DR
W
A
d3,d2
A
d1,d0
W
W
A
N
....repeat for n data values....
3.3.2.8. Clear SYNC Signal
d3,d2
A
d1,d0
P
(Code 5
)
hex
This command is similar to the normal 20 bit read com-
S
DW
W
A
data_write
A
5,0
A
0,0
W
A
P
mand and uses the same command code C
and
hex
D
for D0 and D1 memory, respectively, however it is
hex
followed by a 4
rather than a 0
.
After a successful decoding of an MPEG frame the sig-
nal at pin SYNC rises and thus generates an interrupt
event for the microcontroller. Issuing this command
lets the signal at pin SYNC return to ‘0’.
hex
hex
2
Example: Read 16 bits of D1:123 has the following I C
protocol:
<DW 68 d4 00
00 01
read 16 bits from D1
1 word to be read
start address
01 23
<DW 69 DR
dd dd >
start reading
and read
Micronas
June 30, 2004; 6251-505-1DS
29
MICRONAS [ MICRONAS ]
