
IBM3206K0424
IBM Processor for Network Resources
Preliminary
The IOP Bus Specific Interface Controller (PCINT)
Page 112 of 676
pnr25.chapt04.01
August 14, 2000
20
Disable retrying on the 1st cycle of 
a memory access.
Setting this bit to 
‘
1
’
 disables the retrying of a memory access to IBM3206K0424. This 
causes a PCI spec violation, but not a data integrity problem. It solves the rare problem 
in which two masters are accessing Control Memory at the same time and retries hap-
pen to both endlessly.
19
Enable writing to special config 
registers
Setting this bit to 
’
1
’
 enables writing to certain registers that are normally read-only. An 
example of this is the vendor and function ID register (PCINT Configuration Word 0).
18
Disable Incremental Latency time-
out retries
Setting this bit to 
’
1
’
 disables PCI retries due to cycles taking more than eight cycles on 
burst accesses after the first access.
17
Enable PCINT Base Address 1 
(I/O for regs)
Setting this bit to 
’
1
’
 enables PCINT Base Address 1 (I/O for registers). This does the 
same function as bit 0 in the PCINT Configuration Word 1 register, but also makes the 
PCINT Base Address 1 (I/O for regs) read back 
’
0
’
s even when written to with values. 
It guards against anything that BIOS code may do to PCINT Configuration Word 1 reg-
ister bit 0 if I/O accesses are not desired.
16
Enable PCINT Base Address 2 
(Mem for regs)
Setting this bit to 
’
1
’
 enables PCINT Base Address 2 (Mem for regs) so IBM3206K0424 
registers can be accessed by PCI memory cycles.
15-12
Encoded Control for PCINT Base 
Address 6 (Memory)
Same as bits 3-0.
11-8
Encoded Control for PCINT Base 
Address 5 (Memory)
7-4
Encoded Control for PCINT Base 
Address 4 (Memory)
3-0
Encoded Control for PCINT Base 
Address 3 (Memory).
Encoding of bits:
X'0': Disable this Base Address. 
X'1': Configured to respond to a 2 GB address size. 
X'2': Configured to respond to a 1 GB address size. 
X'3': Configured to respond to a 512 MB address size. 
X'4': Configured to respond to a 256 MB address size. 
X'5': Configured to respond to a 128 MB address size. 
X'6': Configured to respond to a 64 MB address size. 
X'7': Configured to respond to a 32 MB address size. 
X'8': Configured to respond to a 16 MB address size. 
X'9': Configured to respond to a 8 MB address size. 
X'A': Configured to respond to a 4 MB address size. 
X'B': Configured to respond to a 2 MB address size. 
X'C': Configured to respond to a 1 MB address size. 
X'D': Configured to respond to a 64K address size, and enables internal windowing of 
memory. 
X'E': Configured to respond to a 32K address size, and enables internal windowing of 
memory. 
X'F': Configured to respond to a 16K address size, and enables internal window
Bit(s)
Function
Description