Altera External Memory PHY Interface User Manual

Page 30

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3–14

Chapter 3: Functional Description—ALTMEMPHY (nonAFI)

ALTMEMPHY Signals

External Memory PHY Interface (ALTMEMPHY) (nonAFI) Megafunction User Guide

© January 2010

Altera Corporation

ctl_doing_rd

input

1

The active-high signal from the controller specifying
that a read command has been issued to the external
RAM.

For more information, see

“Handshake Mechanism

Between Read Commands and Read Data” on
page 3–47

.

ctl_init_done

input

1

The memory controller drives this active-high signal
to specify that the controller has initialized the
memory and the calibration process should begin.

ctl_negedge_en

input

1

This signal is used if ADDR_CMD_NEGEDGE_EN is
set to EXT_SELECT. If true, the address and
command signals are output on the falling edge of
the address and command clock, ac_clk_2x. If
false, the address and command signals are output
on the rising edge of the address and command
clock. When set to EXT_SELECT, the
ctl_negedge_en

top level input determines

whether the edge is used.

ctl_read_req

output

1

The active-high signal requesting a read command to
the address on the ctl_address bus.

ctl_ready

input

1

The controller-ready signal which indicates that the
currently asserted read or write request has been
accepted. The address of the request is sampled
when both the ready and request signals are high.

ctl_size

output

LOCAL_

BURST_LEN_

BITS

The output to the controller indicating the size
(length) of the burst transfer, fixed at 1 for this
version.

ctl_usr_mode_rdy

output

1

The ALTMEMPHY sequencer logic drives this
active-high signal to specify the ALTMEMPHY has
finished its calibration and is ready to accept user
read or write requests.

ctl_wdata

output

LOCAL_IF_

DWIDTH

The write data from the ALTMEMPHY to the
controller. The ALTMEMPHY sequencer logic drives
ctl_wdata

during calibration. ctl_wdata has

the same timing as local_wdata.

ctl_wdata_req

input

1

The controller-request for write data; not required
when the controller has an Avalon-MM interface.

The memory controller that the ALTMEMPHY
sequencer uses during calibration drives
ctl_wdata_req

. Same timing as

local_wdata_req

.

ctl_write_req

output

1

The active-high signal specifying that a write
command should be issued to the address on the
ctl_address

signal. The ALTMEMPHY

sequencer logic drives ctl_write_req during
calibration. Same timing as local_write_req.

Table 3–6. Interface to the Memory Controller for DDR2 and DDR SDRAM—nonAFI

(Note 1)

(Part 2 of 3)

Signal Name

Type

Width

Description

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