MC68MH360EM25L Freescale Semiconductor, MC68MH360EM25L Datasheet - Page 647

• Manufacturer Part Number: MC68MH360EM25L
• Description: IC MPU QUICC ETHER 25MHZ 240FQFP
• Manufacturer: Freescale Semiconductor

Specifications of MC68MH360EM25L

• Processor Type: M683xx 32-Bit
• Speed: 25MHz
• Voltage: 5V
• Mounting Type: Surface Mount
• Package / Case: 240-FQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Features: -

7.12.5.3.4 Receiver Buffer Descriptor Pointer (RBPTR). The RBPTR for each SPI chan-
nel points to the next BD that the receiver will transfer data to when it is in idle state or to the
current BD during frame processing. After a reset or when the end of the BD table is
reached, the CP initializes this pointer to the value programmed in the RBASE entry.
Although RBPTR need never be written by the user in most applications, it may be modified
by the user when the receiver is disabled or when the user is sure that no receive buffer is
currently in use.
7.12.5.3.5 Transmitter Buffer Descriptor Pointer (TBPTR). The TBPTR for each SPI
channel points to the next BD that the transmitter will transfer data from when it is in idle
state or to the current BD during frame transmission. After a reset or when the end of BD
table is reached, the CP initializes this pointer to the value programmed in the TBASE entry.
Although TBPTR need never be written by the user in most applications, it may be modified
by the user when the transmitter is disabled or when the user is sure that no transmit buffer
is currently in use.
7.12.5.3.6 Other General Parameters. Additional parameters are listed in Table 7-16.
These parameters do not need to be accessed by the user in normal operation, and are
listed only because they may provide helpful information for experienced users and for
debugging.
The Rx and Tx internal data pointers are updated by the SDMA channels to show the next
address in the buffer to be accessed.
The Tx internal byte count is a down-count value that is initialized with the Tx BD data length
and decremented with every byte read by the SDMA channels. The Rx internal byte count
is a down-count value that is initialized with the MRBLR value and decremented with every
byte written by the SDMA channels.
The Rx internal state, Tx internal state, Rx temp, Tx temp, and reserved areas are for RISC
use only.
7.12.5.4 SPI COMMANDS. The following transmit and receive commands are issued to the
CR.
7.12.5.4.1 INIT TX PARAMETERS Command. This command initializes all transmit
parameters in this serial channel’s parameter RAM to their reset state. This command
should only be issued when the transmitter is disabled. Note that the INIT TX AND RX
PARAMETERS command may also be used to reset both transmit and receive parameters.
7.12.5.4.2 CLOSE Rx BD Command. The CLOSE Rx BD command is used to force the
SPI controller to close the current Rx BD, if it is currently being used, and to use the next BD
for any subsequent data that is received. If the SPI controller is not in the process of receiv-
ing data, no action is taken by this command.
MOTOROLA
To extract data from a partially full buffer, the CLOSE Rx BD
command may be used.
Freescale Semiconductor, Inc.
For More Information On This Product,
MC68360 USER’S MANUAL
Go to: www.freescale.com
NOTE
Serial Peripheral Interface (SPI)
7-323