RapidIO Intel FPGA IP User Guide

ID 683884
Date 9/15/2021
Public
Document Table of Contents

6.2.13. Doorbell Message Registers

The RapidIO IP core has registers accessible by the Avalon® -MM slave port in the Doorbell module. These registers are described in the following sections.

Table 110.  Doorbell Message Module Memory Map
Address Name Used by
Doorbell Message Space
0x00 Rx Doorbell External Avalon® -MM master that generates or receives doorbell messages.
0x04 Rx Doorbell Status
0x08 Tx Doorbell Control
0x0C Tx Doorbell
0x10 Tx Doorbell Status
0x14 Tx Doorbell Completion
0x18 Tx Doorbell Completion Status
0x1C Tx Doorbell Status Control
0x20 Doorbell Interrupt Enable
0x24 Doorbell Interrupt Status
Table 111.  Rx Doorbell—Offset: 0x00
Field Bits Access Function Default
LARGE_SOURCE_ID (MSB) [31:24] RO Reserved if the system does not support 16-bit device ID. 8'b0
MSB of the DOORBELL message initiator device ID if the system supports 16-bit device ID.
SOURCE_ID [23:16] RO Device ID of the DOORBELL message initiator 8'b0
INFORMATION (MSB) [15:8] RO Received DOORBELL message information field, MSB 8'b0
INFORMATION (LSB) [7:0] RO Received DOORBELL message information field, LSB 8'b0
Table 112.  Rx Doorbell Status—Offset: 0x04
Field Bits Access Function Default
RSRV [31:8] RO Reserved 24’b0
FIFO_LEVEL [7:0] RO Shows the number of available DOORBELL messages in the Rx FIFO. A maximum of 16 received messages is supported. 8'h0
Table 113.  Tx Doorbell Control—Offset: 0x08
Field Bits Access Function Default
RSRV [31:2] RO Reserved 30'h0
PRIORITY [1:0] RW Request Packet’s priority. 2’b11 is not a valid value for the priority field. An attempt to write 2’b11 to this field will be overwritten as 2’b10. 2'h0
Table 114.  Tx Doorbell—Offset: 0x0C
Field Bits Access Function Default
LARGE_DESTINATION_ID (MSB) [31:24] RO Reserved if the system does not support 16-bit device ID. 8'h0
RW MSB of the targeted RapidIO processing element device ID if the system supports 16-bit device ID.
DESTINATION_ID [23:16] RW Device ID of the targeted RapidIO processing element 8'h0
INFORMATION (MSB) [15:8] RW MSB information field of the outbound DOORBELL message 8'h0
INFORMATION (LSB) [7:0] RW LSB information field of the outbound DOORBELL message 8'h0
Table 115.  Tx Doorbell Status—Offset: 0x10
Field Bits Access Function Default
RSRV [31:24] RO Reserved 8'h0
PENDING [23:16] RO Number of DOORBELL messages that have been transmitted, but for which a response has not been received. There can be a maximum of 16 pending DOORBELL messages. 8'h0
TX_FIFO_LEVEL [15:8] RO The number of DOORBELL messages in the staging FIFO plus the number of DOORBELL messages in the Tx FIFO. The maximum value is 16. 8'h0
TXCPL_FIFO_LEVEL [7:0] RO The number of available completed Tx DOORBELL messages in the Tx Completion FIFO. The FIFO can store a maximum of 16. 8'h0
Table 116.  Tx Doorbell Completion—Offset: 0x14
Field61 Bits Access Function Default
LARGE_DESTINATION_ID [31:24] RO Reserved if the system does not support 16-bit device ID. 8'h0
MSB of the targeted RapidIO processing element device ID if the system supports 16-bit device ID.
DESTINATION_ID [23:16] RO The device ID of the targeted RapidIO processing element. 8'h0
INFORMATION [15:8] RO MSB of the information field of an outbound DOORBELL message that has been confirmed as successful or unsuccessful. 8'h0
INFORMATION [7:0] RO LSB of the information field of an outbound DOORBELL message that has been confirmed as successful or unsuccessful. 8'h0
Table 117.  Tx Doorbell Completion Status—Offset: 0x18
Field Bits Access Function Default
RSRV [31:2] RO Reserved 30'h0
ERROR_CODE [1:0] RO This error code corresponds to the most recently read message from the Tx Doorbell Completion register. After software reads the Tx Doorbell Completion register, a read to this register should follow to determine the status of the message.

2'b00—Response DONE status

2'b01—Response with ERROR status

2'b10—Time-out error

2'h0
Table 118.  Tx Doorbell Status Control—Offset: 0x1C
Field Bits Access Function Default
RSRV [31:2] RO Reserved 30'h0
ERROR [1] RW If set, outbound DOORBELL messages that received a response with ERROR status, or were timed out, are stored in the Tx Completion FIFO. Otherwise, no error reporting occurs. 1'h0
COMPLETED [0] RW If set, responses to successful outbound DOORBELL messages are stored in the Tx Completion FIFO. Otherwise, these responses are discarded.18 1'h0
Table 119.  Doorbell Interrupt Enable—Offset: 0x20
Field Bits Access Function Default
RSRV [31:3] RO Reserved 29'b0
TX_CPL_OVERFLOW [2] RW Tx Doorbell Completion Buffer Overflow Interrupt Enable 1'h0
TX_CPL [1] RW Tx Doorbell Completion Interrupt Enable 1'h0
RX [0] RW Doorbell Received Interrupt Enable 1'h0
Table 120.  Doorbell Interrupt Status—Offset: 0x24
Field Bits Access Function Default
RSRV [31:3] RO Reserved 29'h0
TX_CPL_OVERFLOW [2] RW1C Interrupt asserted due to Tx Completion buffer overflow. This bit remains set until at least one entry is read from the Tx Completion FIFO. After reading at least one entry, software should clear this bit. It is not necessary to read all of the Tx Completion FIFO entries. 1'h0
TX_CPL [1] RW1C Interrupt asserted due to Tx completion status 1'h0
RX [0] RW1C Interrupt asserted due to received messages 1'h0
61 The completed Tx DOORBELL message comes directly from the Tx Doorbell Completion FIFO.