Xilinx Zynq-7000 User Manual page 599

Table 4-23: Auxiliary Output Attributes (Cont'd)
Attribute
RD_DURATION_1
WR_CMD_OFFSET_2
WR_DURATION_2
RD_CMD_OFFSET_2
RD_DURATION_2
WR_CMD_OFFSET_3
WR_DURATION_3
RD_CMD_OFFSET_3
RD_DURATION_3
CMD_OFFSET
AO_TOGGLE
The PHY control block has several counters that are not enabled because the synchronous
mode is used where PHY_Clk is 1/2 the frequency of the LPDDR2 SDRAM clock frequency.
At every rising edge of PHY_Clk, a PHY control word is sent to the PHY control block with
information for two memory clock cycles worth of commands and a 2-bit Seq count value.
The write enable to the control FIFO is always asserted and no operation (NOP) commands
are issued between valid commands in the synchronous mode of operation. The Seq count
must be increased with every command sequence of four. The Seq field is used to
synchronize PHY control blocks across multiple I/O banks.
The PHY control block, in conjunction with the PHASER_OUT, generates the write DQS and
the DQ/DQS 3-state control signals during read and write commands.
Zynq-7000 AP SoC and 7 Series FPGAs MIS v4.1
UG586 November 30, 2016
Type Description
This attribute specifies how long in LPDDR2 SDRAM clock cycles the
Vector[5:0]
auxiliary output remains active for a read command.
This attribute specifies how long in LPDDR2 SDRAM clock cycles after the
Vector[5:0] associated write command is executed that the auxiliary output becomes
active.
This attribute specifies how long in LPDDR2 SDRAM clock cycles the
Vector[5:0]
auxiliary output remains active for a write command.
This attribute specifies how long in LPDDR2 SDRAM clock cycles after the
Vector[5:0] associated read command is executed that the auxiliary output becomes
active.
This attribute specifies how long in LPDDR2 SDRAM clock cycles the
Vector[5:0]
auxiliary output remains active for a read command.
This attribute specifies how long in LPDDR2 SDRAM clock cycles after the
Vector[5:0] associated write command is executed that the auxiliary output becomes
active.
This attribute specifies how long in LPDDR2 SDRAM clock cycles the
Vector[5:0]
auxiliary output remains active for a write command.
This attribute specifies how long in LPDDR2 SDRAM clock cycles after the
Vector[5:0] associated read command is executed that the auxiliary output becomes
active.
This attribute specifies how long in LPDDR2 SDRAM clock cycles the
Vector[5:0]
auxiliary output remains active for a read command.
This attribute specifies how long in LPDDR2 SDRAM clock cycles after the
Vector[5:0] associated command is executed that the auxiliary output defined by
AO_TOGGLE toggles.
This attribute specifies which auxiliary outputs are in toggle mode. An
Vector[3:0] auxiliary output in toggle mode is inverted when its associated AO bit is
set in the PHY control word after the CMD_OFFSET has expired.
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Chapter 4: LPDDR2 SDRAM Memory Interface Solution
599
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