idt49c460cjb Integrated Device Technology, idt49c460cjb Datasheet - Page 8

• Manufacturer Part Number: idt49c460cjb
• Description: 32-bit Cmos Error Detection And Correction Unit
• Manufacturer: Integrated Device Technology

IDT49C460/A/B/C/D/E
32-BIT CMOS ERROR DETECTION AND CORRECTION UNIT
OPERATING MODE SELECTION
IDT49C460s. The Diagnostic Mode pins — DIAG MODE
— define four basic areas of operation.
CORRECT further divide operation into 8 functions, with
CODE ID
outputs SC
check bits as stored in the Diagnostic Latch.
errors on the outputs
errors are not corrected in this mode. The syndrome bits are
provided on the outputs SC
Mode, the syndrome bits are generated by comparing the
internally generated check bits from the Data In Latch with
DATA
DATA
SC
NC
Tables 2 and 3 describe the nine operating modes of the
Generate Mode is used to display the check bits on the
Detect Mode provides an indication of errors or multiple
7
Code ID
63
0–31
0–31
BYTE
S
SC
6
0
0
1
1
/C
6
1,0
6
HIGH
56
CB
7
0–7
1
S
SC
defining the ninth mode as the Internal Mode.
5
7
55
/C
BYTE
. The Diagnostic Generate Mode displays
5
5
Figure 1. 32-Bit Configuration
CB
C
S
IDT49C460
SC
Table 4. Slice Identification
6
4
/C
48
6
6
Code ID
4
4
ERROR
CB
47
C
S
BYTE
5
SC
31
3
0
1
0
1
5
/C
BYTE
3
3
C
CB
40
0
4
0–7
5
S
SC
4
2
24
and
/C
3
39
. For the Diagnostic Detect
2
C
CB
BYTE
2
23
3
32-Bit
Internal Control Mode
64-Bit, Lower 32–Bit (0–31)
64-Bit, Upper 32-Bit (32–63)
BYTE
3
S
MULT ERROR
SC
1
/C
DATA
C
CB
32
4
1
2
1
DATA
16
2
2
31
S
Slice Selected
CODE ID
SC
BYTE
0
CB
C
15
/C
BYTE
1
0
GENERATE
0
1
24
3
CB
C
0
1,0
1
23
8
0
BYTE
. Single bit
Figure 3. 32-Bit Data Format
Figure 4. 64-Bit Data Format
7
2584 drw 05
BYTE
2584 tbl 04
16
2
and
15
0
0
BYTE
0,0
0,1
11.6
C
0
1
check bits stored in the diagnostic latch rather than with the
check bit latch contents.
single bit errors will be complemented (corrected) and made
available as input to the Data Out Latches.
Diagnostic Correct Mode will correct single bit errors as
determined by syndrome bits generated from the data input
and contents of the diagnostic latches.
Data Input Latches are set, latched to a logic zero and made
available as input to the Data Out Latches.
MODE
Latch. Even CODE ID
code, can be redefined from the Diagnostic Latch data.
8
7
Correct Mode is similar to the Detect Mode except that
The Initialize Mode provides check bits for all zero bit data.
The Internal Mode disables the external control pins DIAG
BYTE
C
DATA
1
0,1
DATA INPUT
32–63
0
32
C
0
CHECK BITS
and CORRECT to be defined by the Diagnostic
2
MILITARY AND COMMERCIAL TEMPERATURE RANGES
ERROR
ERROR
C
0
DATA
C
DATA
(LOWER 32 BITS)
DATA
(UPPER 32 BITS)
3
Figure 2. 64-Bit Configuration
C
IDT49C460
IDT49C460
0–31
32
1
CHECK–BIT INPUTS
MULT
ERROR
MULT
ERROR
C
SC
4
1,0
CB
C
0–7
2
CB
, although externally set to the 01
8
0–7
SYNDROME/
C
CHECK BITS
8
CHECK BITS
CODE ID
CODE ID
5
0–7
SC
2584 drw 07
C
3
0–7
8
C
OE
OE
6
C
SC
1,0
SC
1,0
4
C
5
1,0
1,1
IDT74FCT240
C
2584 drw 06
6
1/8
2584 drw 08
Again, the
C
OE
7
SC
8