#### 21.4.6 Cell Broadband Engine SPU architecture

When gdb is debugging the Cell Broadband Engine SPU architecture, it provides the following special commands:

`info spu event`
  Display SPU event facility status. Shows current event mask and pending event status.
`info spu signal`
  Display SPU signal notification facility status. Shows pending signal-control word and signal notification mode of both signal notification channels.
`info spu mailbox`
  Display SPU mailbox facility status. Shows all pending entries, in order of processing, in each of the SPU Write Outbound, SPU Write Outbound Interrupt, and SPU Read Inbound mailboxes.
`info spu dma`
  Display MFC DMA status. Shows all pending commands in the MFC DMA queue. For each entry, opcode, tag, class IDs, effective and local store addresses and transfer size are shown.
`info spu proxydma`
  Display MFC Proxy-DMA status. Shows all pending commands in the MFC Proxy-DMA queue. For each entry, opcode, tag, class IDs, effective and local store addresses and transfer size are shown.