MC68302EH16C Freescale Semiconductor, MC68302EH16C Datasheet - Page 169

• Manufacturer Part Number: MC68302EH16C
• Description: IC MPU MULTI-PROTOCOL 132-PQFP
• Manufacturer: Freescale Semiconductor

Specifications of MC68302EH16C

• Processor Type: M683xx 32-Bit
• Speed: 16MHz
• Voltage: 5V
• Mounting Type: Surface Mount
• Package / Case: 132-MQFP, 132-PQFP
• Controller Family/series: 68K
• Core Size: 32 Bit
• Ram Memory Size: 1152Byte
• Cpu Speed: 16MHz
• No. Of Timers: 3
• Embedded Interface Type: SCP, TDM
• Digital Ic Case Style: PQFP
• Rohs Compliant: Yes
• Family Name: M68000
• Device Core: ColdFire
• Device Core Size: 32b
• Frequency (max): 16MHz
• Instruction Set Architecture: RISC
• Supply Voltage 1 (typ): 5V
• Operating Temp Range: 0C to 70C
• Operating Temperature Classification: Commercial
• Mounting: Surface Mount
• Pin Count: 132
• Package Type: PQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

4.5.11.5 UART Command Set
These commands are issued to the command register described in 4.3 Command Set.
STOP TRANSMIT Command
RESTART TRANSMIT Command
ENTER HUNT MODE Command
MOTOROLA
After a hardware or software reset and the enabling of the channel by writing the SCC
mode register, the channel is in the transmit enable mode and starts polling the first BD
in the table approximately every eight transmit clocks.
The channel STOP TRANSMIT command disables the transmission of characters on the
transmit channel. If this command is received by the UART controller during message
transmission, transmission of that message is aborted. The UART completes transmis-
sion of any data already transferred to the UART FIFO (up to three characters) and then
stops transmitting data. The TBD# is not advanced.
The UART transmitter will transmit a programmable number of break sequences and then
start to transmit idles. The number of break sequences (which may be zero) should be
written to the break count register (BRKCR) before this command is given to the UART
controller.
The STOP TRANSMIT command must be issued before the SCC mode register is used
to disable the transmitter if the transmitter will be reenabled at a later time.
The channel RESTART TRANSMIT command re-enables the transmission of characters
on the transmit channel. This command is expected by the UART in three situations: after
issuing a STOP TRANSMIT command, after issuing a STOP TRANSMIT and then dis-
abling the channel using the SCC mode register, or after transmitter errors (CTS lost). The
UART controller will resume transmission from the current transmitter BD number (TBD#)
in the channel's Tx BD table.
If the transmitter is being re-enabled, the RESTART TRANSMIT command must be used
and should be followed by the enabling of the transmitter in the SCC mode register.
After a hardware or software reset and the enabling of the channel by its SCC mode reg-
ister, the channel is in the receive enable mode and will use the first BD in the table.
The ENTER HUNT MODE command is used to force the UART controller to abort recep-
tion of the current message, generate an RX interrupt (if enabled) as the buffer is closed,
and enter the hunt mode. The UART controller will resume reception using the next BD
once an address character or a single idle character is received. In multidrop hunt mode,
the UART controller continually scans the input data stream for the address character.
While not in multidrop mode, the UART controller will wait for a single IDLE character. In
the UART mode, none of the data received in the FIFO is lost when ENTER HUNT MODE
command is issued; however, this command does reset the receive FIFO in other proto-
cols, e.g., HDLC.
If an enabled receiver has been disabled by clearing ENR in the SCC mode register, the
ENTER HUNT MODE command must be given to the channel before setting ENR again.
Reception will then begin with the next BD.
MC68302 USER’S MANUAL
Communications Processor (CP)
4-49