LSI Logic Confidential
15-46
Serial I/O Port
Copyright © 2001, 2002 by LSI Logic Corporation. All rights reserved.
into the “current buffer” address registers (ADDR_PTR3
and ADDR_PTR4) in double-buffer mode operation. (See
Note on <Hyperactive>page 42.)
Go is set by software after the address range for the “next
buffer” is programmed (ADDR_PTR1/ADDR_PTR2).
Go is cleared by the hardware after these “next values”
are loaded. It is also cleared on reset.
MODE
Transfer Mode Select
2
This bit must always be set to ‘1’ so that the channel
operates in double-buffer mode.
FLUS
FIFO Flush
1
This is a self-clearing bit for flushing the DMA channel’s
two internal FIFOs.
When FLUS is set for transmit channels, all data currently
in the channel FIFOs is dropped.
When FLUS is set for receive channels, all data currently
in the channel FIFOs is sent to the SDRAM address indi-
cated by ADDR_PTR3.
Setting FLUS does not terminate a transfer; it merely
dumps data (if transmit) or sends whatever data remains
in the FIFOs up to the SDRAM (if receive).
CHEN
DMA Channel Enable
0
This bit enables/disables the DMA channel. If CHEN is
cleared during a DMA operation, DMA is paused. Set
CHEN again to resume the DMA operation. All state
information is preserved when DMA is paused, and the
DMA operation continues from where it left off.
CHEN is controlled by software. It must be cleared once
the DMA operation has finished. On reset, CHEN is 0.
IDC DMA Receive Status Register (IDC_RX_STATUS_REG_ADDR)
Offset = 0xBE00E4
Read/Write
Default = 0x0000 0000
31
20
19
18
16
Reserved
FLSTS
FLVLB