Visible to Intel only — GUID: lro1402319664483
Ixiasoft
Visible to Intel only — GUID: lro1402319664483
Ixiasoft
31.5.2. Control Register
Bit | Name | Description |
---|---|---|
31:6 | <reserved> | Reserved. |
5 | Stop Descriptors | Setting this bit stops the SGDMA dispatcher from issuing more descriptors to the read or write hosts. Read the stopped status register to determine when the dispatcher stopped issuing commands and the read and write hosts are idle. |
4 | Global Interrupt Enable Mask | Setting this bit will allow interrupts to propagate to the interrupt sender port. This mask occurs before the register logic so any interrupt events that are triggered when the mask is disabled will not be latched by IRQ register bit in status register. |
3 | Stop on Early Termination | Setting this bit stops the SGDMA from issuing more read/write commands to the host modules if the write host attempts to write more data than the user specifies in the length field for packet transactions. The length field is used to limit how much data can be sent and is always enabled for packet based writes. |
2 | Stop on Error | Setting this bit stops the SGDMA from issuing more read/write commands to the host modules if an error enters the write host module sink port. |
1 | Reset Dispatcher | Setting this bit resets the registers and FIFOs of the dispatcher and host modules. Since resets can take multiple clock cycles to complete due to transfers being in flight on the fabric, you should read the resetting status register to determine when a full reset cycle has completed. |
0 | Stop Dispatcher | Setting this bit stops the SGDMA in the middle of a transaction. If a read or write operation is occurring, then the access is allowed to complete. Read the stopped status register to determine when the SGDMA has stopped. After reset, the dispatcher core defaults to a start mode of operation. |
The response agent port of mSGDMA contains registers providing information of the executed transaction. This register map is only applicable when the response mode is enabled and set to memory mapped. Also when the response port is enabled, it needs to have responses read because it buffers responses. When setup as a memory-mapped agent port, reading byte offset 0x7 outputs the response. If the response FIFO becomes full the dispatcher stops issuing transfer commands to the read and write hosts. The following describes the registers definition.
Byte Lanes | |||||
---|---|---|---|---|---|
Offset | Access | 3 | 2 | 1 | 0 |
0x0 | Read | Actual Bytes Transferred[31:0] | |||
0x4 | Read | <reserved>33 | <reserved> | Early Termination34 | Error[7:0] |
The following list explains each of the fields:
- Actual bytes transferred determines how many bytes transferred when the mSGDMA is configured in Avalon® -ST to Avlaon-MM mode with packet support enabled. Since packet transfers are terminated by the IP providing the data, this field counts the number of bytes between the start-of-packet (SOP) and end-of-packet (EOP) received by the write host. If the early termination bit of the response is set, then the actual bytes transferred is an underestimate if the transfer is unaligned.
- Error Determines if any errors were issued when the mSGDMA is configured in Avalon® -ST to Avlaon-MM mode with error support enabled. Each error bit is persistent so that errors can accumulate throughout the transfer.
- Early Termination determines if a transfer terminates because the transfer length is exceeded when the SGDMA is configured in Avalon® -ST to Avalon® -MM mode with packet support enabled. This bit is set when the number of bytes transferred exceeds the transfer length set in the descriptor before the end-of-packet is received by the write host.