
ISA bus
2-6
MCF5249UM
MOTOROLA
2.6
ISA BUS
The MCF5249 supports an ISA bus. (No ISA DMA channel). Using the ISA bus protocol, reads and writes
to up to two ISA bus peripherals are possible. For the first peripheral, CS2/IDE-DIOR/GPIO13 and
IDE-DIOW/GPIO14 are the read and write strobe. For the second peripheral, CS3/SRE/GPIO11 and
SWE/GPIO12 are the read and write strobe. Either peripheral can insert wait states by pulling
IDE-IORDY/GPIO16
2.7
BUS BUFFER SIGNALS
As the MCF5249 has a quite complicated slave bus, with the possibility to put DRAM on the bus, put
asynchronous memories on the bus, and to put ISA bus peripherals on the bus, it may become necessary
to introduce a bus buffer on the bus. The MCF5249 has a glueless interface to steer these bus buffers with
2 bus buffer output signals BUFENB1/GPIO57 and BUFENB2/GPIO7.
Note: The BUFENB2 signal is only used in the 160 MAPBGA package.
2.8
I2C MODULE SIGNALS
There are two I2C interfaces on this device.
The I2C module acts as a quick two-wire, bidirectional serial interface between the MCF5249 processor
and peripherals with an I2C interface (e.g., LED controller, A-to-D converter, D-to-A converter). When
devices connected to the I2C bus drive the bus, they will either drive logic-0 or high-impedance. This can
be accomplished with an open-drain output.
2.9
SERIAL MODULE SIGNALS
The following signals transfer serial data between the two UART modules and external peripherals.
All serial module signals can be used as gpi or gpo. The GPIO-FUNCTION and GPIO1-FUNCTION
registers must be programmed to determine pin functions of the inputs and outputs. If used as gpo or gpi,
UART functionality is lost.
Table 2-3 I2C Module Signals
I2C MODULE SIGNAL
DESCRIPTION
I2C Serial Clock
The SCL/QPSICLK and SCL2/GPIO3 bidirectional signals are
the clock signal for first and second I2C module operation. The
I2C module controls this signal when the bus is in master
mode; all I2C devices drive this signal to synchronize I2C
timing.
Signals are multiplexed
Function select is done via PLLCR register.
I2C Serial Data
The SDA/QSPI_DIN and SDA2/GPIO55 bidirectional signals
are the data input/output for the first and second serial I2C
interface.
Signals are multiplexed
Function select is done via PLLCR register.
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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