mpc823rg Freescale Semiconductor, Inc, mpc823rg Datasheet - Page 654

• Manufacturer Part Number: mpc823rg
• Description: Mpc823 Powerquicc Integrated Communications Processor For Portable Systems
• Manufacturer: Freescale Semiconductor, Inc

Communication Processor Module
• MAX_IDL—Once a character is received, the SCCx UART controller begins counting
• IDLC—The RISC microcontroller uses this value to store the current idle counter value
• BRKCR—The SCCx UART controller sends a break character sequence whenever a
• PAREC, FRMEC, NOSEC, and BRKEC—You must initialize these 16-bit (modulo–2
• BRKLN—This value is used to store the length of the last break character that is
• UADDR1, UADDR2—In multidrop mode, the SCCx UART controller provides
• TOSEQ—This value is used to transmit out-of-sequence characters in the transmit
• CHARACTER1 to CHARACTER 8—These characters define the receive control
• RCCM—This value is used to mask the comparison of the CHARACTER1 to
any idle characters that are received. If a MAX_IDL number of idle characters is
received before the next data character, an idle timeout occurs and the buffer is closed.
This, in turn, can produce an interrupt request to the core to receive the data from the
buffer. Thus, MAX_IDL provides a convenient way to demarcate frames in UART mode.
To disable the MAX_IDL feature, simply program it to 0x0000. An idle character is
calculated the following number of bit times: 1 + data length (5, 6, 7, or 8) + 1 (if parity
bit is used) + number of stop bits (1 or 2). For example, for 8 data bits, no parity, and 1
stop bit, the character length is 10 bits.
in the MAX_IDL timeout process. IDLC is a down-counter and you do not need to
initialize or access it.
STOP TRANSMIT command is issued to the CPCR. The number of break characters
sent by the SCCx UART controller is determined by the value in BRKCR. For 8 data
bits, no parity, 1 stop bit, and 1 start bit, each break character is 10 bits long and
consists of all zeros.
counters. When the following conditions occur, they are incremented by the RISC
microcontroller.
received and is as long as the break. For example, if the receive pin is low for 20 bit
times, BRKLN shows the value 0x0010. BRKLN is accurate to within one character unit
of bits. For 8 data bits, no parity, 1 stop bit, and 1 start bit, BRKLN is accurate to within
10 bits.
automatic address recognition for two addresses. In this case, you program the lower
order bytes of UADDR1 and UADDR2 with the two preferred addresses.
stream. Using this field, the preferred characters can be inserted into the transmit FIFO
without affecting any transmit buffer that might currently be in progress.
characters on which interrupts can be generated.
CHARACTER 8 parameters so that classes of control characters can be defined. A one
enables the bit comparison and a zero masks it.
PAREC counts received parity errors.
FRMEC counts received characters with framing errors.
NOSEC counts received characters with noise errors.
BRKEC counts the number of break conditions that occur on the receivepin. Notice
that one break condition can last for hundreds of bit times, yet this counter is
incremented only once during that period.
Freescale Semiconductor, Inc.
For More Information On This Product,
MPC823 REFERENCE MANUAL
Go to: www.freescale.com
MOTOROLA
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