Toshiba TMPR4937 Manual page 316

Bit Mnemonic Field Name
Current PCI Bus
4:0 CPAS
Arbiter State
Figure 10.4.28 PCI Bus Arbiter Current State Register (2/2)
Description
Current PCI Bus Arbiter State (Default: 0x00)
Displays the State Machine that was selected by the FSM bit.
Please refer to Figures 12.5.3 and 12.11.1 for an explanation of
Agent/Grant A - W and Level 2.
When FSM =1:
0x00: Preparation state for transferring bus ownership to PCI Agent A.
0x01: State in which Grant A is provided to PCI Agent A when PCI Bus
ownership is being held elsewhere.
0x02: State in which Grant A is provided to PCI Agent A when PCI Bus
ownership is not being held elsewhere.
0x03: The agent that was provided Grant A exists in this state. If there is
bus ownership, the PCI Bus Arbiter transfers bus ownership to
another agent.
0x04: Preparation state for transferring bus ownership to PCI Agent B.
0x05: State in which Grant B is provided to PCI Agent B when PCI Bus
ownership is being held elsewhere.
0x06: State in which Grant B is provided to PCI Agent B when PCI Bus
ownership is not being held elsewhere.
0x07: The agent that was provided Grant B exists in this state. If there is
bus ownership, the PCI Bus Arbiter transfers bus ownership to
another agent.
0x08: Preparation state for transferring bus ownership to PCI Agent C.
0x09: State in which Grant C is provided to PCI Agent C when PCI Bus
ownership is being held elsewhere.
0x0A: State in which Grant C is provided to PCI Agent C when PCI Bus
ownership is not being held elsewhere.
0x0B: The agent that was provided Grant C exists in this state. If there is
bus ownership, the PCI Bus Arbiter transfers bus ownership to
another agent.
0x0C: Preparation state for transferring bus ownership to PCI Agent D.
0x0D: State in which Grant D is provided to PCI Agent D when PCI Bus
ownership is being held elsewhere.
0x0E: State in which Grant D is provided to PCI Agent D when PCI Bus
ownership is not being held elsewhere.
0x0F: The agent that was provided Grant D exists in this state. If there is
bus ownership, the PCI Bus Arbiter transfers bus ownership to
another agent.
0x10: Preparation state for transferring bus ownership to PCI Agent Level
2.
0x11: State in which Grant Level 2 is provided to PCI Agent Level 2 when
PCI Bus ownership is being held elsewhere.
0x12: State in which Grant Level 2 is provided to PCI Agent Level 2 when
PCI Bus ownership is not being held elsewhere.
0x13: The agent that was provided Grant Level 2 exists in this state. If
there is bus ownership, the PCI Bus Arbiter transfers bus ownership
to another agent.
When FSM=0, the FSM=1 description is replaced as follows: A→W, B→X,
C→Y, D→Z, Level 2→N/A.
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Chapter 10 PCI Controller
Read/Write
R