EP80579 Datasheet, PDF (769/1916 Pages) Intel Corporation – Intel® EP80579 Integrated Processor Product Line

Intel^® EP80579 Integrated Processor
20.2.1.4 Offset C6h: DMA_BCC[5-7] - DMA Base and Current Count Registers
for Channels 5-7
Table 20-7. Offset C6h: DMA_BCC[5-7] - DMA Base and Current Count
Registers for Channels 5-7
Description: Ch. 5: C6h - C7h, Ch. 6: CAh - CBh,Ch. 7: CEh - CFh
View: IA F
Base Address: 0000h (IO)
Size: 16 bit^a
Default: XXXX
Offset Start: C6h at 04h
Offset End: C7h at 04h
Power Well: Core
Bit Range Bit Acronym
Bit Description
Sticky
Bit Reset
Value
Bit Access
15 : 00
BCCNT
Base and Current Count: This register determines the
number of transfers to be performed. The address
specified points to two separate registers. On writes, the
value is stored in the Base Count register and copied to
the Current Count register. On reads, the value is returned
from the Current Count register.
The actual number of transfers is one more than the
number programmed in the Base Count Register (i.e.,
programming a count of 4h results in 5 transfers). The
count is decremented in the Current Count register after
each transfer. When the value in the register rolls from
zero to FFFFh, a terminal count is generated. If the
channel is in auto-initialize mode, the Current Count
register is reloaded from the Base Count register after a
terminal count is generated. For transfers to/from an 8-bit
slave (channels 0-3), the count register indicates the
number of bytes to be transferred. For transfers to/from a
16-bit slave (channels 5-7), the count register indicates
the number of words to be transferred.
The register is accessed in 8-bit quantities. The byte is
pointed to by the current byte pointer flip/flop. Before
accessing a count register, the byte pointer flip/flop must
be cleared to ensure that the lowest byte is accessed first.
XXXXh
RW
a. This register provides an 8-bit window into a 16-bit quantity. The byte accessed depends on the current byte pointer flip/flop.
August 2009
Order Number: 320066-003US
Intel^® EP80579 Integrated Processor Product Line Datasheet
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