LH543620M-20 Просмотр технического описания (PDF) - Sharp Electronics
Номер в каталоге
Компоненты Описание
Список матч
LH543620M-20 Datasheet PDF : 38 Pages
| |||
LH543620
Byte-Order-Reversal and Bus Funneling/
Defunneling Functions
Word width can be selected at the Input Port and/or
the Output Port to be 36, 18 or 9 bits wide. When the
Output Port width is selected to be 36 bits, it is possible
to select Byte-Order-Reversal.
The funneling mechanism is controlled by the inputs
WSI[1:0] and WSO[1:0] according to Tables 2 and 5. Data
is packed and unpacked from a 36-bit word memory array.
Table 7 describes all combinations of funneling/defunneling.
Changes to the funneling/defunneling settings during
system operation should be made one clock before a
word boundary, as shown in Example 3.
Example 1: 36-to-9 Funneling
CONDITIONS
WSI[1:0] WSO[1:0]
3
–
–
0
RESULTS
Input 36 bits wide.
Output 9 bits wide.
Pins used are Q[8:0].
The dataflow structure is illustrated by Figure 5.
1024 × 36 Synchronous FIFO
Example 2: 18-to-36 Defunneling With Byte Reversal
This example performs two functions:
1. Bus width change
2. Big Endian to Little Endian conversion
This configuration can be used for connecting the Intel
80286 to the Motorola 68040.
CONDITIONS
WSI[1:0] WSO[1:0]
1
–
–
2
RESULTS
Input 18 bits wide.
Pins used are D[17:0].
Output 36 bits wide with byte
order reversal.
The dataflow structure is illustrated by Figure 6.
Example 3: Changing Input Bus Width From 9 to 36
During Operation
CKI WSI
ACTION
0
0 Write 1st 9-bit byte
1
0 Write 2nd 9-bit byte
2
0 Write 3rd 9-bit byte
3
3 Write 4th 9-bit byte
4
3 Write 1st 36-bit word
Table 7. Bus Funneling/Defunneling *
CKI
cycles
0
1
2
3
4
5
6
7
8
0
1
2
3
4
0
1
INPUT
WSI = 0
D[35:9] D[8:0]
xxx
B0
xxx
B1
xxx
B2
xxx
B3
xxx
B4
xxx
B5
xxx
B6
xxx
B7
xxx
B8
WSI = 1
D[35:18] D[17:0]
xx B1 B0
xx B3 B2
xx B5 B4
xx B7 B6
xx B9 B8
WSI = 3
D[35:0]
B3 B2 B1 B0
B7 B6 B5 B4
CKO
cycles
0
1
2
3
4
5
6
7
8
0
1
2
3
4
0
1
* NOTE: B0, B1, . . ., represent data bytes.
OUTPUT
WSO = 3
WSO = 2
WSO = 1
WSO = 0
Q[35:0]
Q[35:0]
Q[35:18] Q[17:0]
Q[35:9]
Q[8:0]
B3 B2 B1 B0 B0 B1 B2 B3 B3 B2 B1 B0 B3 B2 B1 B0
B7 B6 B5 B4 B4 B5 B6 B7 B1 B0 B3 B2 B0 B3 B2 B1
B7 B6 B5 B4 B1 B0 B3 B2
B5 B4 B7 B6 B2 B1 B0 B3
B7 B6 B5 B4
WSO = 3
WSO = 2
WSO = 1
WSO = 0
Q[35:0]
Q[35:0]
Q[35:18] Q[17:0]
Q[35:9]
Q[8:0]
B3 B2 B1 B0 B0 B1 B2 B3 B3 B2 B1 B0 B3 B2 B1 B0
B7 B6 B5 B4 B4 B5 B6 B7 B1 B0 B3 B2 B0 B3 B2 B1
B7 B6 B5 B4 B1 B0 B3 B2
B5 B4 B7 B6 B2 B1 B0 B3
WSO = 3
WSO = 2
WSO = 1
B7 B6 B5 B4
WSO = 0
Q[35:0]
Q[35:0]
Q[35:18] Q[17:0]
Q[35:9]
Q[8:0]
B3 B2 B1 B0 B0 B1 B2 B3 B3 B2 B1 B0 B3 B2 B1 B0
B7 B6 B5 B4 B4 B5 B6 B7 B1 B0 B3 B2 B0 B3 B2 B1
B7 B6 B5 B4 B1 B0 B3 B2
B5 B4 B7 B6 B2 B1 B0 B3
B7 B6 B5 B4
14
Share Link: 