12. Register Descriptions
304
PowerSpan II User Manual
80A1010_MA001_09
Integrated Device Technology
www.idt.com
12.5.33
Processor Bus Miscellaneous Control and Status Register
Register Name: PB_MISC_CSR
Register Offset: 0x2C0
PCI
Bits
Function
PB
Bits
31-24
PowerSpan II Reserved
0-7
23-16
PowerSpan II Reserved
8-15
15-08
PowerSpan II Reserved
MAX_RETRY
16-23
07-00
EXT
CYC
MAC_
TEA
MODE_
7400
TEA_EN
ARTRY_
EN
DP_EN
AP_EN
PARITY
24-31
Name
Type
Reset
By
Reset
State
Function
MAX_RETRY
[3:0]
R/W
PB_RST
0
Maximum number of retries. Except for 0000, all entries are
multiples of 64 retries
0000 = retry forever
0001 = 64 retries
0010 = 128 retries
0011 = 192 retries, etc.
EXTCYC
R/W
PB_RST
0
Determines if the PowerSpan II PB master is enabled to
generate extended cycles (16 byte or 24 byte)
This ability improves performance of PowerQUICC II
systems. The EXTCYC bit must be set to 0 in order to ensure
compatibility with WinPath and other PowerPC devices.
0 = Cannot generate extended cycle
1= Can generate extended cycle
MAC_TEA
R/W
PB_RST
1
Master-Abort Configuration Error Mapping
This bit controls the handling of a Master-Abort while a
PowerSpan II PCI Master is generating a configuration
transaction initiated by a processor bus master. If MAC_TEA
is cleared, the processor bus slave returns all ones to the
initiating processor bus master. If MAC_TEA is cleared and
TEA_EN is set to 1, the processor bus slave asserts
PB_TEA_ to terminate the transaction initiated by the
processor.
0 = Assert PB_TEA_ when Master-Abort occurs on PCI
configuration cycles
1 = Return all “1s” when Master-Abort occurs on PCI
configuration cycles