RXQUEUE

RXQUEUE

Receive/Transmit Queue Information.

Type

USHORT  cch
USHORT  cb

C Declaration Method

typedef struct

Fields

cch

Number of characters in the queue.

Binary integer with the number of characters received/to be transmitted in the physical device driver receive/transmit queue. This is a memory buffer between the memory pointed to by the READ/WRITE request packet and the receive/transmit hardware for this COM device.

cb

Size of receive/transmit queue.

Binary integer with the size of the physical device driver receive/transmit queue. Applications should be independent of the receive/transmit queue size (fixed or not fixed). The information in this field allows the application to get the size of the receive/transmit queue, but is subject to change. The current size of the receive queue is approximately 1KB.

Using this information, the application should avoid device driver receive queue overruns by using an application-to-application block protocol with the system communicating with the application.

Comment

The behavior of data movement between the READ/WRITE request and the receive/transmit queue can change with each release of the physical device driver. Applications should not be dependent on this information.