
Chapter 6: Functional Description—High-Performance Controller II 6–21
Example Top-Level File
June 2011 Altera Corporation External Memory Interface Handbook Volume 3
Section I. DDR and DDR2 SDRAM Controllers with ALTMEMPHY IP User Guide
■ Low-power mode operation
The example driver requests the controller to place the memory into power-down
and self-refresh states, and hold it in those states for the amount of time specified
by the
COUNTER_VALUE
signal. You can vary this value to adjust the duration the
memory is kept in the low-power states. This test is only available if your
controller variation enables the low-power mode option.
The example driver has four outputs that allow you to observe which tests are
currently running and if the tests are passing. The pass not fail (
pnf
) signal goes low
once one or more errors occur and remains low. The pass not fail per byte
(
pnf_per_byte
) signal goes low when there is incorrect data in a byte but goes back
high again once correct data is observed in the following byte. The
test_status
signal
indicates the test that is currently running, allowing you to determine which test has
failed. The
test_complete
signal goes high for a single clock cycle at the end of the set
of tests.
Table 6–11 shows the bit mapping for each test status.
Table 6–12 shows the ALTMEMPHY Debug interface signals, which are located in
<variation_name>_phy.v/vhd file.
Table 6–11. Test Status[] Bit Mapping
Bit Test
0 Sequential address test
1 Incomplete write test
2 Data mask pin test
3 Address pin test
4 Power-down test
5 Self-refresh test
6 Auto-precharge test
Table 6–12. ALTMEMPHY Debug Interface Signals
Signal Name Direction Description
d/jointfilesconvert/1708784/bg_clk
Input Debug interface clock
d/jointfilesconvert/1708784/bg_addr
Input Debug interface address
d/jointfilesconvert/1708784/bg_cs
Input Debug interface chip select
d/jointfilesconvert/1708784/bg_wr
Input Debug interface write request
d/jointfilesconvert/1708784/bg_wr_data
Input Debug interface write data
d/jointfilesconvert/1708784/bg_rd
Input Debug interface read request
d/jointfilesconvert/1708784/bg_rd_data
Input Debug interface read data
d/jointfilesconvert/1708784/bg_waitrequest
Output Debug interface wait request
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