MIPS R10000 Microprocessor User's Manual - SGI TechPubs Library

System Interface Operations 129
External Double/Single/Partial-Word Data Response Protocol
Cycle
SysClk
Master
SysReq*
SysGnt*
SysRel*
SysCmd(11:0)
SysCmdPar
SysAD(63:0)
SysADChk(7:0)
SysVal*
SysRdRdy*
SysWrRdy*
SysState(2:0)
SysStatePar
SysStateVal*
SysResp(4:0)
SysRespPar
SysRespVal*
An external agent may issue an external double/single/partial-word data
response in response to a processor double/single/partial-word read request.
An external agent issues an external double/single/partial-word data response
with a single data cycle; the data cycle consists of:
• asserting SysCmd[11]
• driving the request number associated with the corresponding
processor request on SysCmd[10:8]
• driving the data quality indication on SysCmd[5]
• driving the response last data type indication on SysCmd[4:3]
• driving the ECC check indication on SysCmd[0]
• driving the data on SysAD[63:0]
• asserting SysVal*
Figure 6-18 depicts a processor double/single/partial-word read request and the
corresponding external double/single/partial-word data response.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
P0 P0 P0 P0 P0 P0 - EA - P0 P0 P0 P0 P0 P0 P0 P0 DSPRd RspLst
Adr Dat
Figure 6-18 External Double/Single/Partial-Word Data Response Protocol
MIPS R10000 Microprocessor User's Manual Version 2.0 of January 29, 1997