ORSPI4 datasheet(44/263 Pages) LATTICE

44 / 263 page

Lattice Semiconductor

ORCA ORSPI4 Data Sheet

Figure 15. 128-Bit Write Protocol

SPI4 Transmit Interface - Detailed Description

The FPGA transmit interface provides a simple FIFO-like interface, simplifying write accesses. Asserting the cor-

rect 3-bit address with the associated write enable signal causes transmit data and sideband control signals to be

registered for writes to a FIFO partition within the DPRAMs. When addressing a particular FIFO partition within the

DPRAM, the associated FIFO ﬁll level of the addressed partition is immediately reﬂected back to the FPGA,

enabling the user to monitor the current ﬁll level of a particular partition. Based upon the conﬁgured ﬁll level, a logic

'1' on the FIFO_FULL signal will indicate either a 3/4-full condition or a completely full condition for the indexed par-

tition.

Transmit DPRAMs

There are four DPRAMs referred to as banks 0, 1, 2 and 3. Each bank has a 32-bit data interface to the FPGA.

Each DPRAM has its own individual write enable and write clock allowing it to be written by the FPGA application

independently.

Each DPRAM bank is conﬁgured by software to operate in either 32-bit, 64-bit or 128-bit aggregation mode. Every

DPRAM bank is also conﬁgured to contain 1, 2, 4 or 8 virtual FIFOs. The user determines the number of FIFOs

depending on the number of ports and buffer requirements for the ports as required by a given application. The pro-

gramming of a DPRAM bank in 32-bit, 64-bit or 128-bit mode and programming of the number of virtual FIFOs

within a DPRAM bank is done through software as shown in Table 8. Note that in 64-bit mode, DPRAMs 0 and 1

must be conﬁgured identically. The combined DPRAM pair is referred to as DPRAM “0”. Similarly DPRAM pairs 2

and 3 must be conﬁgured identically. This combined DPRAM pair is referred to as DPRAM “2”. In 128-bit mode, all

DPRAMs must be conﬁgured identically. The combined DPRAM banks are collectively referred to as DPRAM “0”.

The aggregation modes can be used in ﬁve possible combinations as shown in Table 6. The size of the embedded

data and control FIFOs for each mode is shown in Table 7. The user accesses a virtual FIFO using the 3-bit FIFO

read address (refer to Table 2, Table 3, and Table 4) from the FPGA. Table 5 shows the indexed partition based

upon the conﬁgured DPRAM partitioning and aggregation mode.

SPIA_TX128_CLK

SPIA_TX128_WD_CNT_RST

123

SPIA_TX128_ADDR[2:0]

SPIA_TX128_WE

SPIA_TX128_DATA[127:0]

SPIA_TX128_SOP

SPIA_TX128_EOP

SPIA_TX128_PORT[15:0]

SPIA_TX128_BE[7:0]

Part. Addr 'k'

0xFFFF

Port 3

Port 7

Port 2

Addr 'j'

NOTE: SPIB is identical to SPIA

0xFFFF

0xFFF8

0xFFFF

Partition Addr 'j+4'

ORSPI4 Datasheet(PDF) 44 Page - Lattice Semiconductor

ORSPI4 Datasheet(HTML) 44 Page - Lattice Semiconductor

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL