Sundance Spas ST201 User Manual
Page 80
80
Sundance Technology
ST201
PRELIMINARY draft 2
TXDMAPOLLPERIOD
Class....................I/O Registers, DMA
Base Address ......IoBaseAddress register value
Address Offset .....0x0a
Access Mode .......Read/Write
Width ...................8 bits
The value in TxDMAPollPeriod determines the interval at which the current TFD is polled. When a zero
TxDMANextPtr is fetched from the current TFD, TxDMANextPtr is polled to determine when a new TFD is
ready to be processed. Polling is disabled when TxDMAPollPeriod is cleared. TxDMAPollPeriod is cleared
by reset. The value in TxDMAPollPeriod represents a multiple of 320 ns time intervals. The maximum
value is 127 (or 40.64 us).
BIT
BIT NAME
BIT DESCRIPTION
6..0
TxDMAPollPeriod
The number of 320ns intervals between polls of the TxDMANextPtr
field of the current TFD.
7
Unused
This bit is ignored.