M54455EVB User’s Manual, Rev. 4
10
Freescale Semiconductor
are set on the CPLD mode signals (CPLD_MODE[1:0]). The CPLD_MODE signals are set by the CPLD
configuration switch, SW1. See
shows the SW1 settings
and their corresponding boot mode configurations.
4.3.1
Default Configuration (SW1[2:1] = ON:ON)
If the BOOTMOD pins are 00 during reset, the MCF5445
x
RCON register determines the chip
configuration after reset, regardless of the states of the external data pins. The RCON register specifies the
following default configuration for the MCF54455:
•
PCI enabled, muxed Flexbus address/data, 8-bit port-size boot
•
PLL enabled
•
PCI host mode
•
66MHz PCI slew rate mode
•
PLL multiplier:
f
VCO
= 6
×
f
REF
4.3.2
Parallel Configuration (SW1[2:1] = OFF:ON)
If the BOOTMOD pins are 10 during reset, the MCF5445
x
configuration after reset is determined
according to the levels driven onto the FB_AD[7:0] pins. On the M54455EVB, the FB_AD[7:0] pins are
actively driven by an 8-bit buffer enabled when the MCF5445
x
RSTOUT signal is asserted. The values
driven by the buffer are set by the SW3 DIP switch settings. Refer to
information.
Table 3. M54455EVB Boot Mode Selection
BOOTMOD[1:0]
SW1[2:1]
Meaning
00
ON:ON
Boot from Flexbus with defaults (from RCON register)
01
ON:OFF
Reserved
10
OFF:ON
Boot from Flexbus and override defaults via data bus (FB_AD[7:0])
11
OFF:OFF
Boot from Flexbus and override defaults via serial boot facility (SPI memory)