ep1m120 Altera Corporation, ep1m120 Datasheet - Page 44

• Manufacturer Part Number: ep1m120
• Description: Programmable Logic Device Family
• Manufacturer: Altera Corporation

Mercury Programmable Logic Device Family Data Sheet
44
Figure 23. Encoded CAM Address Outputs
Figure 24. Unencoded CAM Address Outputs
Notes to
(1)
(2)
In single-match mode, it takes two clock cycles to write into CAM, but
only one clock cycle to read from CAM. In this mode, both encoded and
unencoded outputs are available without external logic. Single-match
mode is better suited for designs without duplicate data in the memory.
data[30..0] =45 (1)
select (2)
data[31..0] = 45
For an unencoded output, the ESB only supports 31 input data bits. One input bit
is used by the select line to choose one of the two banks of 16 outputs.
If the select input is a 1, then CAM outputs odd words between 1 through 15. If
the select input is a 0, CAM outputs words even words between 0 through 14.
Figure
24:
CAM
CAM
Data
Data
15
27
45
85
15
27
45
85
Address
Address
10
11
12
13
10
11
12
13
addr[15..0] = 12
match = 1
q12
q13
q14
q15
q0
Altera Corporation
Encoded Output
Unencoded outputs.
q12 goes high to
signify a match.