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DS785UM1
Copyright 2007 Cirrus Logic
DMA Controller
EP93xx User’s Guide
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STATUS
Address:
Channel Base A 0x000C - Read Only
Definition:
This is the channel status register, which is a read-only register, used to
provide status information with respect to the DMA channel.
Bit Descriptions:
RSVD:
Reserved. Unknown During Read.
Stall:
A “1” indicates channel is stalled and cannot currently
transfer data because a base address has not been
programmed. When the channel is first enabled, the Stall
bit is suppressed until the first buffer has been transferred,
that is, no stall interrupt generated when STALL state
entered from IDLE state, only when entered from ON
State. The STALL state can be cleared by writing a base
address or disabling the DMA channel. The reason for
channel completion can be ascertained by reading the
BYTES_REMAINING register, if it is zero, the channel was
stopped by the DMA Channel; if it is non-zero, the
peripheral ended transfer with TxEnd/RxEnd. If the
transfer ended with error, ChError bit/interrupt is set.
NFB:
A “1” indicates the Channel FSM has moved from NEXT
State to ON State. This means that the channel is currently
transferring data from a DMA buffer but the next base
address for the next buffer in the transfer has not been
programmed, and may now be.
0 - Not in ON State, not ready for next buffer update.
1 - In ON State, ready for next buffer BASE/MAXCOUNT
updates. NFB interrupt generated if not masked.
ChError:
Indicates error status of buffer transfer:
0 - The last buffer transfer completed without error.
1 - The last buffer transfer terminated with an error.
BYTES:
This is the number of valid DMA data currently stored by
the channel in the DMA Controller in packer or unpacker.
Usually used for test/debug.
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RSVD
15
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1
0
RSVD
BYTES
NextBuffer
Current State
ChError
RSVD
NFB
STALL
Summary of Contents for EP93 Series
Page 28: ...P 6 DS785UM1 Copyright 2007 Cirrus Logic Preface EP93xx User s Guide PP P ...
Page 162: ...5 36 DS785UM1 Copyright 2007 Cirrus Logic System Controller EP93xx User s Guide 55 5 ...
Page 576: ...15 18 DS785UM1 Copyright 2007 Cirrus Logic UART2 EP93xx User s Guide 1515 15 ...
Page 634: ...17 38 DS785UM1 Copyright 2007 Cirrus Logic IrDA EP93xx User s Guide 1717 17 ...
Page 648: ...19 6 DS785UM1 Copyright 2007 Cirrus Logic Watchdog Timer EP93xx User s Guide 1919 19 ...
Page 688: ...21 32 DS785UM1 Copyright 2007 Cirrus Logic I2S Controller EP93xx User s Guide 2121 21 ...
Page 790: ...27 20 DS785UM1 Copyright 2007 Cirrus Logic IDE Interface EP93xx User s Guide 2727 27 ...
Page 808: ...28 18 DS785UM1 Copyright 2007 Cirrus Logic GPIO Interface EP93xx User s Guide 2828 28 ...