MCF548x Reference Manual, Rev. 3
19-4 Freescale Semiconductor

19.2.13 Target Ready (PCITRDY)

The PCITRDY signal is asserted active low by the currently addressed target to indicate that it is ready to
complete the current data phase.

19.3 Memory Map/Register Definition

The MCF548x has several sets of registers that control and report status for the different interfaces to the
PCI controller: PCI Type 0 configuration space registers, general status/control registers, and
communication subsystem interface registers. All of these registers are accessible as offsets of MBAR. As
an XL bus master, an external PCI bus master can access MBAR space for register updates.
PCIRESET is controlled by a bit in the register space, PCIGSCR[PR], and must first be cleared before
external PCI devices wake-up. In other words, an external PCI master cannot load configuration software
across the PCI bus until this bit is cleared by software. Access to all internal registers is supported
regardless of the value held in PCIGSCR[PR].
All registers are accessible at an offset of MBAR in the memory space. There are two module offsets for
PCI configuration space. One is allocated to the communication subsystem interface registers and the other
to all other PCI controller registers including the standard Type 0 PCI configuration space. Software reads
from unimplemented registers return 0x00000000 and writes have no effect.
Table 19-2. PCI Memory Map
Address Name Size Description Access
PCI Type 0 Configuration Registers
MBAR + 0xB00 PCIIDR 32 PCI Device ID/Vendor ID R
MBAR + 0xB04 PCISCR 32 PCI Status/Command R/W
MBAR + 0xB08 PCICCRIR 32 PCI Class Code/Revision ID R
MBAR + 0xB0C PCICR1 32 PCI Configuration 1 Register R/W
MBAR + 0xB10 PCIBAR0 32 PCI Base Address Register 0 R/W
MBAR + 0xB14 PCIBAR1 32 PCI Base Address Register 1 R/W
MBAR + 0xB18–0xB24 Reserved
MBAR + 0xB28 PCICCPR 32 PCI Cardbus CIS Pointer R/W
MBAR + 0xB2C PCISID 32 Subsystem ID/Subsystem Vendor ID R/W
MBAR + 0xB30 PCIERBAR 32 PCI Expansion ROM R/W
MBAR + 0xB34 PCICPR 32 PCI Capabilities Pointer R/W
MBAR + 0xB38 Reserved
MBAR + 0xB3C PCICR2 32 PCI Configuration Register 2 R/W
MBAR + 0xB40–0xB5C Reserved
General Control/Status Registers
MBAR + 0xB60 PCIGSCR 32 Global Status/Control Register R/W
MBAR + 0xB64 PCITBATR0 32 Target Base Address Translation Register
0
R/W