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Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network Processors—Synchronous Serial Port
Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network Processors
Developer’s Manual
August 2006
872
Order Number: 306262-004US
20.5.4
SSP Interrupt Test Register (SSITR)
Writing “1” to the corresponding bit position to the SSP Interrupt Test register
generates an interrupt strobe signal to the Interrupt Controller or a DMA request for
test purposes.
Note:
SSITR functionality is available even when the SSP is disabled.
20.5.5
SSP Data Register (SSDR)
The SSP Data Register (SSDR) is a block of 32-bit locations that can be accessed by 32-
bit data transfers. The SSDR represents two physical registers: the first is temporary
storage for data on its way out through the Transmit FIFO, the other is temporary
storage for data coming in through the Receive FIFO.
As the register is accessed by the system, FIFO control logic transfers data
automatically between register and FIFO as fast as the system moves it. Data in the
FIFO shifts up or down to accommodate the new word (unless it is an attempted WRITE
to a full Transmit FIFO). Status bits are available to show the system whether either
buffer is full, above/below a programmable threshold, or empty.
4
BSY
SSP is busy
0 = SSP is idle or disabled
1 = SSP currently transmitting or receiving a frame
0
RO
3
RNE
Receive FIFO not empty.
0 - Receive FIFO is empty
1 - Receive FIFO is not empty
0
RO
2
TNF
Transmit FIFO not Full.
0 = Transmit FIFO is full
1 = Transmit FIFO is not full
1
RO
1:0
(Reserved)
(Reserved)
00
RV
Register
SSSR (Sheet 2 of 2)
Bits
Name
Description
Reset Value
Access
Register Name:
SSITR
Block
Base Address:
0xC801_20
Offset Address
0x0C
Reset Value
0x0000_0000
Register Description:
SSP Interrupt Test Register
Access:
(See below.)
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8
7
6
5
4
3
2
1
0
Reserved
TRO
R
TRF
S
TT
FS
Reserved
Register
SSITR
Bits
Name
Description
Reset Value
Access
31:08
(Reserved)
(Reserved)
0x0000
RV
7
TROR
Test Receive FIFO overrun (ROR)
0x0000
RW
6
TRFS
Test Receive FIFO service request (RFS)
0x0000
RW
5
TTFS
Test Transmit FIFO service request (TFS)
0x0000
RW
4:0
(Reserved)
(Reserved)
0x0000
RV