MSC8144E Reference Manual, Rev. 3
18-4
Freescale
Semiconductor
QUICC Engine™ Subsystem
18.2.2
Peripheral Interface
The RISC processors use the peripheral bus to communicate with all of its UCCs. Each controller
has separate receive and transmit 192-byte FIFOs.
18.2.3
Parameter RAM
The QUICC Engine subsystem maintains a section in the multi-user RAM that contains the
associated parameter values for the operation of the UCCs and SPI. Each peripheral has an
associated page in the parameter RAM. The exact definition of the parameter RAM for each
peripheral is in the protocol descriptions in the QUICC Engine™ Block Reference Manual with
Protocol Interworking (QEIWRM). The size of the parameter RAM page differs from protocol to
protocol. The minimum size of the parameter RAM page assigned to any protocol is 64 bytes.
The base address of the parameter RAM page must be aligned to 64 bytes.
Some parameter RAM values must be initialized before the UCC is enabled. The QUICC Engine
subsystem initializes or writes other values. Once initialized, most parameter RAM values need
not be accessed by user software, because most activity centers around the TxBDs and RxBDs
rather than the parameter RAM. However, if the parameter RAM is accessed, note the following:
You can read the parameter RAM at any time.
You can write to the Tx parameter RAM only when the transmitter is disabled (that is,
after a
STOP
TRANSMIT
command or after the buffer/frame finishes transmitting after a
GRACEFUL
STOP
TRANSMIT
command and before a
RESTART
TRANSMIT
command).
You can write to the Rx parameter RAM only when the receiver is disabled. The
CLOSE
RX
BD
command does not stop reception, but it does allow the user to extract data from a
partially full Rx buffer.
After reset, the QUICC Engine subsystem initializes the base addresses of the parameter RAM
pages for all the UCCs to default values. You can override the default values by issuing the
A
SSIGN
P
AGE
command to the QUICC Engine subsystem. The advantage of using the
A
SSIGN
P
AGE
command is that you can arrange the parameter RAM area efficiently (with no unused areas)
according to the specific peripherals/protocols used in your system.
Table 18-1 lists the default values of the parameter RAM pages base addresses assigned by the
QUICC Engine subsystem to the different peripherals.
Table 18-1. Default Parameter RAM Base Addresses
Address Offset
Peripheral
Size
(Bytes)
0x8400
UCC 1 (Rx and Tx)
256
0x8600
UCC 3 (Rx and Tx)
256
0x8000
UCC 5 (Rx and Tx)
256
0x8900
SPI (Rx and Tx)
128
Summary of Contents for MSC8144E
Page 1: ...MSC8144E Reference Manual Quad Core Media Signal Processor MSC8144ERM Rev 3 July 2009 ...
Page 48: ...MSC8144E Reference Manual Rev 3 xlviii Freescale Semiconductor ...
Page 86: ...MSC8144E Reference Manual Rev 3 1 38 Freescale Semiconductor Overview ...
Page 168: ...MSC8144E Reference Manual Rev 3 3 60 Freescale Semiconductor External Signals ...
Page 242: ...MSC8144E Reference Manual Rev 3 5 26 Freescale Semiconductor Reset ...
Page 314: ...MSC8144E Reference Manual Rev 3 8 24 Freescale Semiconductor General Configuration Registers ...
Page 414: ...MSC8144E Reference Manual Rev 3 10 14 Freescale Semiconductor MSC8144E SC3400 DSP Subsystem ...
Page 452: ...MSC8144E Reference Manual Rev 3 11 38 Freescale Semiconductor Internal Memory Subsystem ...
Page 520: ...MSC8144E Reference Manual Rev 3 12 68 Freescale Semiconductor DDR SDRAM Memory Controller ...
Page 1070: ...MSC8144E Reference Manual Rev 3 21 28 Freescale Semiconductor Timers ...