User guide

7–12 Chapter 7: Functional Description—High-Performance Controller II
Top-level Signals Description
External Memory Interface Handbook Volume 3 December 2010 Altera Corporation
Section II. DDR3 SDRAM Controller 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 7–3 shows the bit mapping for each test status.
Top-level Signals Description
Table 7–4 shows the clock and reset signals.
Table 7–3. 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 7–4. Clock and Reset Signals (Part 1 of 2)
Name Direction Description
global_reset_n Input
The asynchronous reset input to the controller. All other reset signals
are derived from resynchronized versions of this signal. This signal
holds the complete ALTMEMPHY megafunction, including the PLL, in
reset while low.
pll_ref_clk Input The reference clock input to PLL.
phy_clk Output
The system clock that the ALTMEMPHY megafunction provides to the
user. All user inputs to and outputs from the DDR3 HPC II must be
synchronous to this clock.
reset_phy_clk_n Output
The reset signal that the ALTMEMPHY megafunction provides to the
user. It is asserted asynchronously and deasserted synchronously to
phy_clk clock domain.