ep1m120 Altera Corporation, ep1m120 Datasheet - Page 42

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

Mercury Programmable Logic Device Family Data Sheet
Figure 21. ESB in Single-Port Mode
Notes to
(1)
(2)
42
All registers can be asynchronously cleared by ESB local interconnect signals, global signals, or chip-wide reset.
If there is only one single-port RAM block in an ESB, it can support the following configurations: 4,096 1; 2,048
Figure
address[ ]
outclken
outclock
inclken
inclock
data[ ]
wren
21:
Dedicated Clocks
4
Dedicated Fast
Global Signals
Single-Port Mode
The Mercury device’s ESB also supports a single-port mode, which is used
when simultaneous reads and writes are not required. See
single ESB can support up to two single-port mode RAMs.
6
Content-Addressable Memory
Mercury devices can implement CAM in ESBs. CAM can be thought of as
the inverse of RAM. RAM stores data in a specific location; when the
system submits an address, the RAM block provides the data. Conversely,
when the system submits data to CAM, the CAM block provides the
address where the data is found. For example, if the data FA12 is stored
in address 14, the CAM outputs 14 when FA12 is driven into it.
or
Note (1)
D
ENA
D
ENA
Q
Q
D
ENA
Generator
Pulse
Write
Q
Data In
Address
Write Enable
RAM/ROM (2)
1,024
2,048
Data Out
128
256
512
16
8
4
2
1
D
ENA
Altera Corporation
Q
Figure
To FastTrack
Interconnect
21. A