CPLD and FPGA
ATCA-8310 Installation and Use (6806800M72D)
285
- Line Status Register (LSR)
This register provides status information to the processor concerning the data transfers. Bits 5
and 6 are showing information about the transmitter section. The rest of the bits contain
information about the receiver.
In non-FIFO mode, three of the LSR register bits, parity error, framing error, and break
interrupt, show the error status of the character that has just been received. In FIFO mode,
these three bits of status are stored with each received character in the FIFO. LSR shows the
status bits of the character at the top of the FIFO. When the character at the top of the FIFO has
errors, the LSR error bits are set and are not cleared until software reads LSR, even if the
character in the FIFO is read and a new character is now at the top of the FIFO.
Bits one through four are the error conditions that produce a receiver line status interrupt when
any of the corresponding conditions are detected and the interrupt is enabled. These bits are
not cleared by reading the erroneous byte from the FIFO or receive buffer. They are cleared only
by reading LSR. In FIFO mode, the line status interrupt occurs only when the erroneous byte is
at the top of the FIFO. If the erroneous byte being received is not at the top of the FIFO, an
interrupt is generated only after the previous bytes are read and the erroneous byte is moved
to the top of the FIFO.
Table 8-59 Line Status Register (LSR)
IO Address: Base + 5
Bit Description
Default
Access
0
Receiver data ready (DR) indicator
DR is set whenever a complete incoming character has been
received and transferred into the RBR or the FIFO. DR is cleared by
reading all of the data in the RBR or the FIFO:
1: New data received
0: No new data
0
GPP: r
Summary of Contents for ATCA-8310
Page 12: ...ATCA 8310 Installation and Use 6806800M72D Contents 12 Contents Contents ...
Page 26: ...ATCA 8310 Installation and Use 6806800M72D 26 List of Figures ...
Page 34: ...ATCA 8310 Installation and Use 6806800M72D About this Manual 34 About this Manual ...
Page 54: ...Hardware Preparation and Installation ATCA 8310 Installation and Use 6806800M72D 54 ...
Page 70: ...Controls Indicators and Connectors ATCA 8310 Installation and Use 6806800M72D 70 ...
Page 162: ...BIOS ATCA 8310 Installation and Use 6806800M72D 162 ...
Page 200: ...U Boot ATCA 8310 Installation and Use 6806800M72D 200 ...
Page 244: ...Intelligent Peripheral Management Controller ATCA 8310 Installation and Use 6806800M72D 244 ...
Page 438: ...CPLD and FPGA ATCA 8310 Installation and Use 6806800M72D 438 ...
Page 442: ...Replacing the Battery ATCA 8310 Installation and Use 6806800M72D 442 ...
Page 444: ...Related Documentation ATCA 8310 Installation and Use 6806800M72D 444 ...
Page 454: ...ATCA 8310 Installation and Use 6806800M72D Sicherheitshinweise 454 ...
Page 456: ...Index ATCA 8310 Installation and Use 6806800M72D 456 ...
Page 457: ...Index ATCA 8310 Installation and Use 6806800M72D 457 ...
Page 458: ...Index ATCA 8310 Installation and Use 6806800M72D 458 ...
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