Altera Internal Memory (RAM and ROM) IP Core - Manual (Page 23)

Memory Block
Types
Single-port RAM (9) Simple dual-port
RAM (10)
True dual-port RAM
Same port RDW Mixed-port RDW Same port RDW (11) Mixed-port RDW (12)
MLAB
Don’t Care
New Data
(14)
New Data
(15)
Old Data
Don’t Care
N/A
MLAB is not supported in true dual-port RAM
M9K
Don’t Care
New Data
(16)
Old Data
Old Data
Don’t Care New Data
(16)
Old Data
Old Data
Don’t Care
M144K
Old Data
Don’t Care New Data
(14)
Old Data
Don’t Care
M10K
Don’t Care
New Data
(14)
Old Data
Don’t Care New Data
(14)
Old Data
Don’t Care
M20K
Old Data
Don’t Care Old Data
Don’t Care New Data
(14)
Old Data
Don’t Care
LCs No parameter
editor (13)
Old Data
Don’t Care N/A
Note: The RDW old data mode is not supported when the Error Correction Code (ECC) is engaged.
Note: If you are not concerned about the output when RDW occurs and would like to improve perform‐
ance, you can select Don't Care. Selecting Don't Care increases the flexibility in the type of
(9) Single-port RAM only supports same-port RDW, and the clocking mode must be either single clock mode,
or input/output clock mode.
(10) Simple dual-port RAM only supports mixed-port RDW, and the clocking mode must be either single clock
mode, or input/output clock mode.
(11) The clocking mode must be either single clock mode, input/output clock mode, or independent clock mode.
(12) The clocking mode must be either single clock mode, or input/output clock mode.
(14) The new data behavior for same-port RDW support NEW_DATA_NO_NBE_READ for x on masked byte
only when the byte enable applies.
(15) Only supported in single clock mode with new data behavior of NEW_DATA_NO_NBE_READ.
(16) There are two types of new data behavior for same-port RDW that you can choose from the parameter
editor. When byte enable is applied, you can choose to read old data, or ‘X’ on the masked byte. The
respective parameter values are:
• NEW_DATA_WITH_NBE_READ for old data on masked byte.
• NEW_DATA_NO_NBE_READ for x on masked byte.
UG-01068
2014.12.17
Selecting RDW Output Choices for Various Memory Blocks 3-13
Embedded Memory Functional Description Altera Corporation
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