PCI Bus Controller
Freescale Semiconductor
22-15
22.3.2.1
Global Status/Control Register (PCIGSCR)
Address: 0xFC0A_8060 (PCIGSCR)
Access: User read/write
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
R DRD
0
PE
SE
ER
AUTODIV
0
0
0
0
0
PRGDIV
W w1c
w1c
w1c
Reset
0
0
0
0
0
—
—
0
0
0
0
0
0
0
0
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
R
DRDE
0
PEE
SEE
ERE
0
0
0
0
0
0
0
0
0
0
PR
W
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
Bits 31,29 and 28 are write-one-to-clear (w1c).
Hardware can set w1c bits, but cannot clear them.
Software can clear w1c bits currently set by writing a 1 to the bit location. Writing a 1 to a w1c bit currently a 0 or
writing a 0 to any w1c bit has no effect.
2
The reset value of bits 26-24 and 18-16 is determined by the PLL multiplier.
Figure 22-15. PCIGSCR Register
Table 22-11.
PCIGSCR Field Descriptions
Field
Description
31
DRD
Delayed read discarded. Set when an internally completed delayed read is discarded due to a non-compliant
or tardy external PCI master. The delayed buffer clears because the master that initiated a target read
transaction to the PCI_BAR
n
register has not retried the transaction in 2
15
(32,768) PCI clocks. Clearing the
buffer allows other target reads to procede to PCI_BAR
n
target space.
Setting of this bit can trigger an interrupt request to the processor if the PCIGSCR[DRDE] bit is set.
30
Reserved, must be cleared.
29
PE
PCI_PERR detected. Set when the PCI parity error signal, PCI_PERR, asserts (any device). A CPU interrupt
is generated if the PCIGSCR[PEE] bit is set. It is up to application software to clear this bit by writing 1 to it.
28
SE
SERR detected. Set when a PCI system error signal, PCI_SERR, asserts (any device). An interrupt is
generated if the PCIGSCR[SEE] bit is set. It is up to application software to clear this bit by writing 1 to it.
27
ER
Error response detected. Set when an internal error occurs during a PCI target transaction. An interrupt is
generated if the PCIGSCR[ERE] bit is set. It is up to application software to clear this bit by writing 1 to it.
26–24
AUTODIV
Auto-detected clock divide. Stores automatically detected internal bus clock to external PCI clock divide ratio.
This field is read-only and the reset value is determined by the ratio detected. Software must read this bit to
determine whether or not the auto-detect logic is functioning correctly. If the register contains a differential
value that does not reflect the PLL settings, PCI controller could malfunction.
000 Reserved
001 Divide by 1
010 Divide by 2
011 Divide by 3
100 Divide by 4
101 Divide by 5
110 Divide by 1.5 (Multiply by
2
/
3
)
111 Reserved
23–19
Reserved, must be cleared.
Summary of Contents for MCF54455
Page 33: ...xxviii Freescale Semiconductor ...
Page 67: ...Freescale Semiconductor 1 ...
Page 125: ...Freescale Semiconductor 1 ...
Page 145: ...Enhanced Multiply Accumulate Unit EMAC 5 21 Freescale Semiconductor ...
Page 173: ...Cache 6 28 Freescale Semiconductor ...
Page 179: ...Static RAM SRAM 7 6 Freescale Semiconductor ...
Page 207: ...Power Management 9 16 Freescale Semiconductor ...
Page 323: ...Reset Controller Module 13 8 Freescale Semiconductor ...
Page 389: ...Pin Multiplexing and Control 16 44 Freescale Semiconductor ...
Page 575: ...PCI Bus Controller 22 58 Freescale Semiconductor ...
Page 600: ...Advanced Technology Attachment ATA Freescale Semiconductor 23 25 ...
Page 601: ...Freescale Semiconductor 1 ...
Page 842: ...I2 C Interface Freescale Semiconductor 33 16 ...
Page 843: ...Freescale Semiconductor 1 ...
Page 921: ...Revision History A 6 Freescale Semiconductor ...