Chip Configuration Module (CCM)
MCF52235 ColdFire® Integrated Microcontroller Reference Manual, Rev. 6
12-6
Freescale Semiconductor
12.4.1
Reset Configuration
During reset, the pins for the reset override functions are immediately configured to known states.
shows the states of the external pins while in reset.
If the RCON pin is not asserted during reset, the chip configuration and the reset configuration pin
functions after reset are determined by RCON or fixed defaults, 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.
If the RCON pin is asserted during reset, then various chip functions, including the reset configuration pin
functions after reset, are configured according to the levels driven onto the external data pins (see
). The internal configuration signals are driven to reflect the levels on the external configuration
pins to allow for module configuration.
12.4.2
Output Pad Strength Configuration
Output pad strength is determined during reset configuration.
12.5
Reset
Reset initializes CCM registers to a known startup state as described in
The CCM controls chip configuration at reset as described in
Table 12-7. Reset Configuration Pin States During Reset
Pin
Pin
Function
1
1
If the external RCON pin is not asserted during reset, pin functions are determined by the default
operation mode defined in the RCON register. If the external RCON pin is asserted, pin functions
are determined by the override values driven on the external data bus pins.
I/O
Output
State
Input
State
RCON
RCON function for all modes
2
2
During reset, the external RCON pin assumes its RCON pin function, but this pin changes to the
function defined by the chip operation mode immediately after reset. See
.
Input
—
Internal weak
pull-up device
Table 12-8. Configuration During Reset
1
1
Modifying the default configurations is possible only if the external RCON pin is asserted.
Pin(s) Affected
Default
Configuration
Override Pins
in Reset
2,
2
The external reset override circuitry drives the data bus pins with the override values while RSTOUT is asserted. It
must stop driving the data bus pins within one CLKOUT cycle after RSTOUT is negated. To prevent contention with
the external reset override circuitry, the reset override pins are forced to inputs during reset and do not become outputs
until at least one CLKOUT cycle after RSTOUT is negated. RCON must also be negated within one cycle after
RSTOUT is negated.
Function
All output pins
RCON[5] = 1
0
Partial strength
1
Full strength
4
Because
of
an
order
from
the
United
States
International
Trade
Commission,
BGA-packaged
product
lines
and
part
numbers
indicated
here
currently
are
not
available
from
Freescale
for
import
or
sale
in
the
United
States
prior
to
September
2010:MCF52234CVM60,
MCF52235CVM60
