AN2866 Freescale Semiconductor / Motorola, AN2866 Datasheet - Page 14

• Manufacturer Part Number: AN2866
• Description: Migrating from the MC68332 to the ColdFire MCF523x
• Manufacturer: Freescale Semiconductor / Motorola

Device Differences
As indicated in the table, the three UARTs on the MCF523x can be externally clocked via the
corresponding DMA timer’s DTIN inputs. This allows for synchronous operation with respect to the
external clock and UART baud rate generation at frequencies totally independent of the internal clock
frequency.
One final feature of the MCF523x UARTs is their ability to trigger a DMA transfer from any programmed
source and destination addresses, when a UART’s receive buffer is either full or not empty or when a
UART’s Transmit buffer is empty.
2.4.1.4
The MC68332 and MCF523x both contain a QSPI module that provide a full-duplex, synchronous serial
peripheral interface for communicating with peripherals and other MCUs. The MCF523x module is based
on the MC68332’s QSPI, so most of the features, control registers, and bit fields are similar if not identical.
Table 3
2.4.1.5
The MC68332 has a single PIT that is capable of generating interrupts at programmable intervals. The
MCF523x has four PITs with similar functionality. As with migrating from the SCI to UARTs, the
migration from the MC68332 PIT to the MCF523x PITs is a move toward more functionality. There should
be very few migration issues as a result of differences between these two modules. In addition to the
increase in the number of timers, the MCF523x offers a wider variety of prescaler and modulus options.
Table 4
14
Programmable 16 entry queue
Slave mode
Master mode
Programmable transfer sizes of 8 to 16 bits in
1-bit increments
Programmable delays before and after
transfers
Programmable QSPI clock phase
Programmable QSPI clock polarity
Wraparound mode
Peripheral chip select lines
Slave select signal
Loopback mode
Programmable peripheral chip select polarity
contrasts the features of the MC68332 and the MCF523x QSPIs.
contrasts the features of the MC68332 and the MCF523x PITs.
Queued Serial Peripheral Interface (QSPI)
Periodic Interrupt Timers (PITs)
Feature
Table 3. MC68332 and MCF523x QSPI Feature Differences
Migrating from the MC68332 to the ColdFire
MC68332
—
√
√
√
√
√
√
√
√
4
√
√
MCF523x
—
—
—
®
√
√
√
√
√
√
√
2
√
MCF523x, Rev. 1.0
in master mode, so no slave select
The MCF523x QSPI only operates
line is needed.
Comments
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