Cyclone Device Handbook, Volume 1
Embedded
Memory
The Cyclone embedded memory consists of columns of M4K memory
blocks. EP1C3 and EP1C6 devices have one column of M4K blocks, while
EP1C12 and EP1C20 devices have two columns (see Table 1–1 on
page 1–2 for total RAM bits per density). Each M4K block can implement
various types of memory with or without parity, including true dual-port,
simple dual-port, and single-port RAM, ROM, and FIFO buffers. The
M4K blocks support the following features:
■ 4,608 RAM bits
■ 250 MHz performance
■ True dual-port memory
■ Simple dual-port memory
■ Single-port memory
■ Byte enable
■ Parity bits
■ Shift register
■ FIFO buffer
■ ROM
■ Mixed clock mode
1
Violating the setup or hold time on the address registers could corrupt the
memory contents. This applies to both read and write operations.
Memory Modes
The M4K memory blocks include input registers that synchronize writes
and output registers to pipeline designs and improve system
performance. M4K blocks offer a true dual-port mode to support any
combination of two-port operations: two reads, two writes, or one read
and one write at two different clock frequencies. Figure 2–12 shows true
dual-port memory.
Figure 2–12. True Dual-Port Memory Configuration
A
dataA[ ]
addressA[ ]
wrenA
clockA
clockenA
qA[ ]
aclrA
B
dataB[ ]
addressB[ ]
wrenB
clockB
clockenB
qB[ ]
aclrB
2–18
Preliminary
Altera Corporation
January 2007