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72
7.1.2
Internal Agent Transaction for Write Request From Initiator
When each active agent register receives a write request, the internal agent operates with the behavior described
in Table 71. This table assumes that StErPkt at 08h = 0, ErrResp at 08h = 0 and AckPnd at 08h = 0.
Table 71. Agent Transaction for Initiator Write Request
STATE
REGISTER
RESPONSE TO
INITIATOR
TSB43AA82 ACTIONS
RESET
AGENT_STATE
ack_type_error
No action
RESET
AGENT_RESET
ack_complete
No action
ORB_POINTER
ack_complete
1. ORB pointer registers 1 and 2 are updated (54h, 58h).
2. Read request packet is loaded into the CTQ.
DOORBELL
ack_complete
The agent’s DrBll at 5Ch is set to 1.
UNSOLICITED_STATE_ENABLE
ack_complete
The agent’s UnStEn at 5Ch is set to 1.
ACTIVE
AGENT_STATE
ack_type_error
No action
ACTIVE
AGENT_RESET
ack_complete
Reset agent state
ORB_POINTER
ack_conflict_error
No action
DOORBELL
ack_complete
The agent’s DrBll at 5Ch is set to 1.
UNSOLICITED_STATE_ENABLE
ack_complete
The agent’s UnStEn at 5Ch is set to 1.
SUSPENDED
AGENT_STATE
ack_type_error
No action
SUSPENDED
AGENT_RESET
ack_complete
Reset agent state
ORB_POINTER
ack_complete
1. ORB pointer registers 1 and 2 are updated (54h, 58h).
2. Read request packet is loaded into the CTQ.
DOORBELL
ack_complete
1. The agent’s DrBll at 5Ch is set to 1.
2. If DrBFtEn (ORB fetch control at 44h) is set to 1, the
read request packet is loaded into the CTQ again.
UNSOLICITED_STATE_ENABLE
ack_complete
The agent’s UnStEn at 5Ch is set to 1.
DEAD
AGENT_STATE
ack_type_error
No action
DEAD
AGENT_RESET
ack_complete
Reset agent state
ORB_POINTER
ack_complete
No action
DOORBELL
ack_complete
The agent’s DrBll at 5Ch is set to 1.
UNSOLICITED_STATE_ENABLE
ack_complete
The agent’s UnStEn at 5Ch is set to 1.
Any state
Reserved agent area
ack_Pending
Stored in ARF
A successful write to a command agent register returns an acknowledge that depends on Ackpnd at 08h, bit 18.
Table 72 shows the command agent response to a successful write.
Table 72. Command Agent Response—Successful Write
Ackpnd
ACKNOWLEDGE SENT
0
ack_complete
1
ack_pending
The AGENT_STATE register (see Section 7.1.1) is a read-only register. A write request to this register from the
initiator results in an ack_type_error. The error response of the TSB43AA82 depends on the settings of StErPkt and
ErrResp (08h bits 15 and 14). Table 73 shows command agent error responses.
Table 73. Command Agent Error Response
StErPkt
ErrResp
Ack TO INITIATOR
RESPONSE PACKET TO INITIATOR AND OTHER ACTIONS
0
1
ack_complete
Received packet is stored in the ARF.
1
0
ack_pending
The packet which has resp_type_error or resp_conflict_error is sent to the initiator.
0
ack_type_error or
ack_conflict_error
No response packet is sent.