Information
PCI Express Interface Controller
MPC8308 PowerQUICC II Pro Processor Reference Manual, Rev. 1
14-74 Freescale Semiconductor
The fields of the PEX_BAR_SEL register are described in Table 14-88.
14.4.7.3 PCI Express BAR Prefetch Configuration Register (PEX_BAR_PF)
PEX_BAR_PF, shown in Figure 14-91, sets the Prefetchable field in the base address registers (BAR) of
the PCI Express configuration space. The local host should program this register before setting the
config-ready bit in the PCI Express configuration space so that the RC host reads the correct information
during enumeration. It is used only in EP mode.
The fields of the PEX_BAR_PF register are described in Table 14-89.
14.4.8 PCI Express Extended Status and Control Registers
14.4.8.1 PME_To_Ack Timeout Register (RC Mode Only)
PEX_PME_TO_ACK_TOR, shown in Figure 14-92, is used to program the timeout value for a
PME_To_Ack message response in terms of PCI Express controller core clock cycles.
Table 14-88. PEX_BAR_SEL Fields Description
Bits Name Description
31–2 — Reserved. Must be zeros.
1–0 SEL Select. Selects the specific BAR size to be programmed by the PEX_BAR_SIZEL and
PEX_BAR_SIZEH registers.
00 PEX_BAR_SIZEL points to BAR0 in address 0x010 (Window 0, 32 bit address).
01 PEX_BAR_SIZEL points to BAR1 in address 0x014 (Window 1, 32 bit address).
10 PEX_BAR_SIZEL points to BAR2 in address 0x018 (low portion of window 2, 64 bit address).
11 PEX_BAR_SIZEL points to BAR4 in address 0x020 (low portion of window 3, 64 bit address).
Offset 0x504 Access: Read/Write
31 43210
R
— PF
W
Reset00000000000000000000010000000000
Figure 14-91. PCI Express BAR Prefetch Configuration Register (PEX_BAR_PF)
Table 14-89. PEX_BAR_PF Fields Description
Bits Name Description
31–4 — Reserved. Must be zeros.
3–0 PF Prefetchable. Sets the prefetchable attribute for all the BARs in the PCI Express configuration
space. Each bit determines the prefetchable attribute of the corresponding BAR.
PF[3] Prefetchable attribute of BAR4 in address 0x020 (low portion of window 3, 64 bit address)
PF[2] Prefetchable attribute of BAR2 in address 0x018 (low portion of window 2, 64 bit address)
PF[1] Prefetchable attribute of BAR1 in address 0x014 (Window 1, 32 bit address)
PF[0] Prefetchable attribute of BAR0 in address 0x010 (Window 0, 32 bit address)