PM8313 datasheet(154/192 Pages) PMC

154 / 192 page

PM8313 D3MX

DATA SHEET

PMC-920702

ISSUE 5

M13 MULTIPLEXER

144

The link state is typically a local software variable. The link state is inactive if the

RFDL is receiving all ones or receiving bit-oriented codes which contain a

sequence of eight ones. The link state is active if the RFDL is receiving flags or

data.

If the RFDL data transfer is operating in the polled mode, then processor

operation is exactly as shown above for the interrupt driven mode, except that the

entry to the service routine is from a timer, rather than an interrupt. In the polled

mode, the option of reading the Status Register first should be used to avoid

unnecessary reads of the Data Register.

The RFDL can also be used with a DMA controller to process the frame data. In

this case, the RDLEOM output is connected to the processor interrupt input. The

RDLINT output of the RFDL is connected through a gate to the DMA request

input of the DMA controller. The gate optionally inhibits the DMA request if the

RDLEOM output is high. The DMA controller reads the data bytes from the

RFDL whenever the RDLINT output is asserted. When the current byte read

from the Data Register is the last byte in a frame (due to an end-of-message or

an abort), or an overrun condition occurs, then the RDLEOM output goes high.

The DMA controller is inhibited from reading any more bytes, and the processor

is interrupted. The processor can then halt the DMA controller, read the Status

data for the next frame.

PM8313 Datasheet(PDF) 154 Page - PMC-Sierra, Inc