mcf5282 Freescale Semiconductor, Inc, mcf5282 Datasheet - Page 438

• Manufacturer Part Number: mcf5282
• Manufacturer: Freescale Semiconductor, Inc

UART Modules
Using a 80-MHz internal bus clock and letting baud rate equal 9600, then
Therefore, UBG1n equals 0x01 and UBG2n equals 0x04.
23.4.1.2.2
An external source clock (DTINn) passes through a divide-by-1 or 16 prescaler. If f
frequency, baud rate can be described with this equation:
23.4.2
Figure 23-18
operating registers, which are described generally in the following sections. For detailed descriptions, refer
to
23.4.2.1
The transmitter is enabled through the UART command register (UCRn). When it is ready to accept a
character, UART sets USRn[TXRDY]. The transmitter converts parallel data from the CPU to a serial bit
stream on UTXDn. It automatically sends a start bit followed by the programmed number of data bits, an
23-18
Section 23.3, “Memory Map/Register
UARTn
Transmit Buffer
(2 Registers)
Transmitter and Receiver Operating Modes
(UTBn)
Transmitter
is a functional block diagram of the transmitter and receiver showing the command and
UART
External Clock
UART Receive
Divider
Buffer (URBn)
(4 Registers)
Figure 23-18. Transmitter and Receiver Functional Diagram
MCF5282 and MCF5216 ColdFire Microcontroller User’s Manual, Rev. 3
=
------------------------------ -
[
32 x 9600
80MHz
Receiver Holding Register 1
UART Command Register (UCRn)
UART Mode Register 1 (UMR1n)
UART Mode Register 2 (UMR2n)
UART Status Register (USRn)
Transmitter Holding Register
Receiver Holding Register 2
Transmitter Shift Register
]
Baudrate
=
Definition.”
Receiver Holding Register 3
260 decimal
Receiver Shift Register
(
=
-------------------- -
(16 or 1)
f
extc
)
=
0x0104 hexadecimal
(
R/W
R/W
R
W
W
R
)
FIFO
extc
Freescale Semiconductor
is the external clock
Interface
UTXDn
External
URXDn
Eqn. 23-2
Eqn. 23-3