Native Loopback Accelerator Functional Unit User Guide for Intel FPGA Programmable Acceleration Card N3000

ID 683693
Date 11/25/2019
Public

2.3. Native Loopback Control and Status Register Descriptions

Table 4.  CSR Names, Addresses and Descriptions
Byte Address (OPAE) Word Address (CCI-P) Access Name Width Description
0x0000 0x0000 RO DFH 64 AF Device Feature Header.
0x0008 0x0002 RO AFU_ID_L 64 AF ID low.
0x0010 0x0004 RO AFU_ID_H 64 AF ID high.
0x0018 0x0006 Rsvd CSR_DFH_RSVD0 64 Mandatory Reserved 0.
0x0020 0x0008 RO CSR_DFH_RSVD1 64 Mandatory Reserved 1.
0x0100 0x0040 RW CSR_SCRATCHPAD0 64 Scratchpad register 0.
0x0108 0x0042 RW CSR_SCRATCHPAD1 64 Scratchpad register 2.
0x0110 0x0044 RW CSR_AFU_DSM_BASEL 32 Lower 32-bits of AF DSM base address. The lower 6 bits are 4x00 because the address is aligned to the 64-byte cache line size.
0x0114 0x0045 RW CSR_AFU_DSM_BASEH 32 Upper 32-bits of AF DSM base address.
0x0120 0x0048 RW CSR_SRC_ADDR 64 Start physical address for source buffer. All read requests target this region.
0x0128 0x004A RW CSR_DST_ADDR 64 Start physical address for destination buffer. All write requests target this region
0x0130 0x004C RW CSR_NUM_LINES 32 Number of cache lines.

0x0138

0x004E

RW

CSR_CTL

32

Controls test flow, start, stop, force completion.
0x0140 0x0050 RW CSR_CFG 32 Configures test parameters.
0x0148 0x0052 RW CSR_INACT_THRESH 32 Inactivity threshold limit.
0x0150 0x0054 RW CSR_INTERRUPT0 32 SW allocates Interrupt APIC ID and Vector to device.
DSM Offset Map
0x0040 0x0010 RO DSM_STATUS 32 Test status and error register.
Table 5.  CSR Bit Fields with ExamplesThis table lists the CSR bit fields that depend on the value of the CSR_NUM_LINES, <N>. In the example below <N> = 14.
Name Bit Field Access Description
CSR_SRC_ADDR [63:<N>] RW 2^(N+6)MB aligned address points to the start of the read buffer.
[<N>-1:0] RW 0x0.
CSR_DST_ADDR [63:<N>] RW 2^(N+6)MB aligned address points to the start of the write buffer.
[<N>-1:0] RW 0x0.
CSR_NUM_LINES [31:<N>] RW 0x0.
[<N>-1:0] RW

Number of cache lines to read or write. This threshold may be different for each test AF.

Note:

Ensure that source and destination buffers are large enough to accommodate the <N> cache lines.

CSR_NUM_LINES should be less than or equal to <N>.

For the following values, assume <N>=14. Then, CSR_SRC_ADDR and CSR_DST_ADDR accept 2^20 (0x100000).

CSR_SRC_ADDR [31:14] RW 1MB aligned address.
[13:0] RW 0x0.
CSR_DST_ADDR [31:14] RW 1MB aligned address.
[13:0] RW 0x0.
CSR_NUM_LINES [31:14] RW 0x0.
[13:0] RW

Number of cache lines to read or write. This threshold may be different for each test AF.

Note: Ensure that source and destination buffers are large enough to accommodate the <N> cache lines.
Table 6.  Additional CSR Bit Fields
Name Bit Field Access Description
CSR_CTL [31:3] RW Reserved.
[2] RW Force test completion. Writes test completion flag and other performance counters to csr_stat. After forcing test completion, the hardware state is identical to a non-forced test completion.
[1] RW Starts test execution.
[0] RW Active low test reset. When low, all configuration parameters change to their default values.
CSR_CFG [29] RW cr_interrupt_testmode tests interrupts. Generates an interrupt at the end of each test.

[28]

RW

cr_interrupt_on_error sends an interrupt when upon error detection.
[27:20] RW

cr_test_cfg configures the behavior of each test mode.

[13:12] RW cr_chsel selects the virtual channel.

[10:9]

RW

cr_rdsel configures the read request type. The encodings have the following valid values:

  • 1'b00: RdLine_S
  • 2'b01: RdLine_I
  • 2'b11: Mixed mode
[8] RW

cr_delay_en enables random delay insertion between requests.

[6:5] RW Configures test mode,cr_multiCL-len. Valid values are 0,1,and 3.
[4:2] RW cr_mode, configures test mode. The following values are valid:
  • 3'b000: LPBK1
  • 3'b001: Read
  • 3'b010: Write
  • 3'b011: TRPUT

For more information about the test mode, refer to the Test Modes topic below.

[1] RW

c_cont selects test rollover or test termination.

  • When 1'b0, the test terminates. Updates the status CSR when CSR_NUM_LINES count is reached.

  • When 1'b1, the test rolls over to the start address after it reaches the CSR_NUM_LINES count. In rollover mode, the test terminates only upon error.

[0] RW

cr_wrthru_en switches between WrLine_I and Wrline_M request types.

  • 1'b0: WrLine_M
  • 1'b1: WrLine_I
CSR_INACT_THRESHOLD [31:0] RW

Inactivity threshold limit. Detects the duration of stalls during a test run. Counts the number of consecutive idle cycles. If the inactivity count > CSR_INACT_THRESHOLD, no requests are sent, no responses are received, and the inact_timeout signal is set.

Writing 1 to CSR_CTL[1] activates this counter.

CSR_INTERRUPT0 [23:16] RW The Interrupt Vector Number for the device.
[15:0] RW apic_id is the APIC OD for the device.
DSM_STATUS [511:256] RO Error dump form Test Mode.
[255:224] RO End Overhead.
[223:192] RO Start Overhead.
[191:160] RO Number of Writes.
[159:128] RO Number of Reads.
[127:64] RO Number of Clocks.
[63:32] RO Test error register.
[31:16] RO Compare and exchange success counter.
[15:1] RO Unique ID for each DSM status write.
[0] RO Test completion flag.

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