Functional Description
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2-35
2
The Hawk’s PCI arbiter has various programming options. It supports 3
different priority schemes: fixed, round robin, and mixed mode. It also
allows various levels of reprioritization programming options within fixed
and mixed modes. Parking can be programmed to any of the requestors, the
last requestor or none. A special bit is added to hold grant asserted for an
agent that initiates a lock cycle. Once a lock cycle is detected, the grant is
held asserted until the PCI LOCK_ pin is released. This feature works only
when the “POL” bit is enabled.
The priority scheme can be programmed by writing the “PRI” field in the
PCI Arbiter control register. The default setting for priority scheme is fixed
mode. The Fixed mode holds each requestor at a fixed level in its
hierarchy. The levels of priority for each requestor are programmable by
writing the “HEIR” field in the PCI Arbiter control register.
describes all available settings for the “HEIR” field in fixed mode.
Notes
1. “000” is the default setting in fixed mode.
2. The HEIR setting only covers a small subset of all possible
combinations. It is the responsibility of the system designer
to connect the request/grant pair in a manner most beneficial
to their design goals.
Table 2-10. Fixed Mode Priority Level Setting
HEIR
Setting
Priority Levels
Highest
Lowest
000
PARB6
PARB5
PARB4
PARB3
PARB2
PARB1
PARB0
HAWK
001
HAWK
PARB6
PARB5
PARB4
PARB3
PARB2
PARB1
PARB0
010
PARB0
HAWK
PARB6
PARB5
PARB4
PARB3
PARB2
PARB1
011
PARB1
PARB0
HAWK
PARB6
PARB5
PARB4
PARB3
PARB2
100
PARB2
PARB1
PARB0
HAWK
PARB6
PARB5
PARB4
PARB3
101
PARB3
PARB2
PARB1
PARB0
HAWK
PARB6
PARB5
PARB4
110
PARB4
PARB3
PARB2
PARB1
PARB0
HAWK
PARB6
PARB5
111
PARB5
PARB4
PARB3
PARB2
PARB1
PARB0
HAWK
PARB6
Summary of Contents for MVME5100 Series
Page 1: ...MVME5100 Single Board Computer Programmer s Reference Guide V5100A PG2 September 2001 Edition ...
Page 16: ...xvi ...
Page 20: ...xx ...
Page 28: ...xxviii ...
Page 62: ...1 34 Computer Group Literature Center Web Site Product Data and Memory Maps 1 ...
Page 278: ...3 88 Computer Group Literature Center Web Site System Memory Controller SMC 3 ...
Page 288: ...4 10 Computer Group Literature Center Web Site Hawk Programming Details 4 ...
Page 320: ...Index IN 12 Computer Group Literature Center Web Site I N D E X ...