Reset Configuration - Freescale Semiconductor MCF54455 Reference Manual

11.4 Functional Description
11.4.1

Reset Configuration

During reset, the pins for the reset override functions are immediately configured to known states.
Table 11-11 shows the states of the external pins while in reset.
Pin
BOOTMOD[1:0]
FB_AD[7:0]
11.4.1.1 Reset Configuration (BOOTMOD[1:0] = 00)
If the BOOTMOD pins are 00 during reset, the RCON register determines the chip configuration after
reset, regardless of the states of the external data pins. The internal configuration signals are driven to
levels specified by the RCON register's reset state for default module configuration.
11.4.1.2 Reset Configuration (BOOTMOD[1:0] = 10)
If the BOOTMOD pins are 10 during reset, the chip configuration after reset is determined according to
the levels driven onto the FB_AD[7:0] pins. (See
driven to reflect the levels on the external configuration pins to allow for module configuration.
The logic levels for reset configuration on FB_AD[7:0] must be actively
driven when BOOTMOD equals 10. The FB_AD[15:8] pins must be
allowed to float or be pulled high.
Freescale Semiconductor
Table 11-11. Reset Configuration Pin States During Reset
Pin Function
BOOTMOD function for all modes
Flexbus address/data functions
(BOOTMO does not equal 10)
Reset configuration data functions
(BOOTMOD equals 10)
I/O
Input Must be driven by external logic
Input
Input Must be driven by external logic
Table 11-12.) The internal configuration signals are
NOTE
Chip Configuration Module (CCM)
Input State
N/A
11-13