5.3.3 Port List

The following table lists the QDR ports.

Table 5-3. QDR Signals and Descriptions1
NameWidthDirectionDescription
Generic Signals
SYS_CLK1OutputClock for User Logic generated by the embedded PLL. All User Interface signals are synchronous to this clock. Always on the global clock network.
RESET_N1InputActive-low asynchronous system reset.
Note: The RESET_N signal must be generated by ANDing the DEVICE_INIT_DONE and BANK_X_CALIB_STATUS signals of the INIT_MONITOR IP core. BANK_X refers to the BANK where the QDR controller is placed.
PLL_REF_CLKInputReference clock to the PLL.
PLL_LOCK1OutputLock signal. This signal is generated by the PLL to indicate that the PLL is locked on to the PLL_REF_CLK signal.
TRAINING_COMPLETE1OutputIndicates that Training is complete.

The user logic must check for TRAINING_COMPLETE = 1 and TRAINING_ERROR = 0 before accessing the QDR memory.

TRAINING_ERROR[2:0]3Output– Bit 0: Reserved

– Bits [2:1]

  • 0: No error.
  • 1: Timeout error, data VALID is received during Q training.
  • 2: No solution found during training.

If no solution is found, restart the Training process described in Training Logic.

User Interface Signals
READ_N4InputRead request with address specified on RADDR bus.
  • 4-bit Wide if Burst Size is 2.
  • 2-bit Wide if Burst Size is 4.
WRITE_N4InputWrite request with address specified on WADDR bus.
  • 4-bit Wide if Burst Size is 2.
  • 2-bit Wide if Burst Size is 4.
WSTRB_NSRAM_DWIDTH/9 * 8InputWrite strobe for write transaction.
WADDRSRAM_AWIDTH*4InputWrite addresses for each beat.

Width is (SRAM_AWIDTH)*4 if burst size is 2, (SRAM_AWIDTH)*2 if burst size is 4

  • In Burst of 2: {ADDR3, ADDR2, ADDR1, ADDR0}
  • In Burst of 4: {ADDR1, ADDR0}
RADDRSRAM_AWIDTH*4InputRead addresses for each beat.

Width is (SRAM_AWIDTH)*4 if burst size is 2, (SRAM_AWIDTH)*2 if burst size is 4

  • In Burst of 2: {ADDR3, ADDR2, ADDR1, ADDR0}
  • In Burst of 4: {ADDR1, ADDR0}
WDATA(SRAM_DWIDTH)*8InputWrite data
RDATA(SRAM_DWIDTH)*8OutputRead data, valid when RVALID is asserted
RVALID1OutputRead data valid
QDR SRAM Interface
D[X:0]9/18/36

(X=8, 17, or 35)

OutputData Output Bus
WPS_N1OutputWrite port select—active-low
BWS0_N1OutputByte write select (BWS) 0—active‐low
BWS1_N1OutputByte write select (BWS) 1—active‐low
BWS2_N1OutputByte write select (BWS) 2—active‐low
BWS3_N1OutputByte write select (BWS) 3—active‐low
A[X:0]218, 19, 20, 21, or 22

(X=17,18,19, 20, or 21)

OutputAddress inputs
Q[X:0]9,18, or 36

(X=8,17, or 35)

InputData input bus
RPS_N1OutputRead port select - active‐low
QVALID1InputValid output indicator. Not used in current QDR subsystem
KP1OutputPositive Clock Output
KN1OutputNegative Clock Output
CQP1InputSynchronous echo Clock input
DOFF_N1OutputInitially, DOFF_N is 0. After calibration, DOFF_N is set to 1.

If Expose DOFF_N port option is selected in the configurator, the DOFF_N signal is exposed and taken care by the QDR controller.

If Expose DOFF_N port option is not selected in the configurator, the DOFF_N signal does not get exposed and must be taken care on the board using a pull-up resistor (check the memory model data sheet).

Note:
  1. In the QDR configurator, the QDR data width field is same as SRAM_DWIDTH. In the QDR configurator, the address width field is same as SRAM_AWIDTH.
  2. The 22-bit address width is supported only for the 18-bit data width.