Statistics Registers

Statistics registers are described in the User Interface beginning with GMAC Octets Transmitted Low Register and ending with GMAC UDP Checksum Errors Register.

The statistics register block begins at 0x100 and runs to 0x1B0, and comprises the registers listed below.

Octets Transmitted Low Register Broadcast Frames Received Register
Octets Transmitted High Register Multicast Frames Received Register
Frames Transmitted Register Pause Frames Received Register
Broadcast Frames Transmitted Register 64 Byte Frames Received Register
Multicast Frames Transmitted Register 65 to 127 Byte Frames Received Register
Pause Frames Transmitted Register 128 to 255 Byte Frames Received Register
64 Byte Frames Transmitted Register 256 to 511 Byte Frames Received Register
65 to 127 Byte Frames Transmitted Register 512 to 1023 Byte Frames Received Register
128 to 255 Byte Frames Transmitted Register 1024 to 1518 Byte Frames Received Register
256 to 511 Byte Frames Transmitted Register 1519 to Maximum Byte Frames Received Register
512 to 1023 Byte Frames Transmitted Register Undersize Frames Received Register
1024 to 1518 Byte Frames Transmitted Register Oversize Frames Received Register
Greater Than 1518 Byte Frames Transmitted Register Jabbers Received Register
Transmit Underruns Register Frame Check Sequence Errors Register
Single Collision Frames Register Length Field Frame Errors Register
Multiple Collision Frames Register Receive Symbol Errors Register
Excessive Collisions Register Alignment Errors Register
Late Collisions Register Receive Resource Errors Register
Deferred Transmission Frames Register Receive Overrun Register
Carrier Sense Errors Register IP Header Checksum Errors Register
Octets Received Low Register TCP Checksum Errors Register
Octets Received High Register UDP Checksum Errors Register
Frames Received Register  

These registers reset to zero on a read and stick at all ones when they count to their maximum value. They should be read frequently enough to prevent loss of data.

The receive statistics registers are only incremented when the receive enable bit (RXEN) is set in the Network Control register.

Once a statistics register has been read, it is automatically cleared. When reading the Octets Transmitted and Octets Received registers, bits 31:0 should be read prior to bits 47:32 to ensure reliable operation.