Chapter 23 Notes on Use of TMPR4937
23-7
<Conditions>
This problem occurs when the following conditions are satisfied.
(1) The broken master detection function is enabled (BMCEN=1).
The broken master detection function is enabled or disabled with the BMCEN bit of the PCI bus
arbiter configuration register (PBACFG). The default value is 0 which disables the function.
(2) The bus masters are assigned to the high level and low level in the on-chip PCI bus arbiter.
The bus master is assigned to the bus arbiter with the PCI Bus Arbiter Request Port Register
(PBAREQPORT).
(3) When the PCI bus master connected to the high level is detected as the broken master, the master
connected to the low level requests the bus mastership, which is the highest-priority request in the
low level. (That is Master W immediately after a reset or the master which acquires the bus
mastership most recently in the low level when the fixed park master mode is not set, or Master W
that is the park master in the fixed park master mode.)
PCI Arbitration Priority
[Workarounds]
There are two workarounds for this problem.
(1) Don’t use the broken master function.
Don’t set the BMCEN bit of the PBACFG register.
(2) When using the broken master function, use only the high level containing Master A, B, C and D.
Low Level
(Priority: Low)
High Level
(Priority: High)
Master A
Low-level
Master
Master Z
Master X
(Park master)
Master W
Master B
Master C
Master D
Master Y
PCI Bus Master 1
PCI Bus Master 2
Request
Request
Grant
Access is not started
within 16PCICLK
Broken Master
PCI bus master 2
also becomes a
broken master.
On-chip PCI Controller
Summary of Contents for TX49 TMPR4937
Page 1: ...64 Bit TX System RISC TX49 Family TMPR4937 Rev 2 0 ...
Page 4: ......
Page 13: ...Table of Contents ix TMPR4937 Revision History 1 ...
Page 14: ...Table of Contents x ...
Page 15: ...Handling Precautions ...
Page 16: ......
Page 18: ...1 Using Toshiba Semiconductors Safely 1 2 ...
Page 40: ...3 General Safety Precautions and Usage Considerations 3 18 ...
Page 42: ...4 Precautions and Usage Considerations 4 2 ...
Page 43: ...TMPR4937 2005 3 Rev 2 0 ...
Page 44: ......
Page 52: ...Chapter 1 Overview and Features 1 6 ...
Page 156: ...Chapter 7 External Bus Controller 7 56 ...
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Page 506: ...Chapter 20 Extended EJTAG Interface 20 8 ...
Page 530: ...Chapter 22 Pinout and Package Information 22 10 ...
Page 542: ...Chapter 24 Parts Number when Ordering 24 2 ...