EMAC8_W - Pin Description

Frozen Content

Modified by Admin on Nov 6, 2013

The following pin description is for the EMAC8_W when used on the schematic. In an OpenBus System, although the same signals are present, the abstract nature of the system hides the pin-level Wishbone interfaces. The external interface signals will be made available as sheet entries, associated with the parent sheet symbol used to reference the underlying OpenBus System.

Table 1. EMAC8_W pin description.

Name	Type	Polarity / Bus size	Description
Control Signals
CLK_I	I	Rise	External (system) clock
RST_I	I	High	External (system) reset
FULL_DPX	I	Level	Duplex select mode: 0 (i.e. connect to GND) = Half Duplex 1 (i.e. connect to VCC) = Full Duplex Note: Using the Controller in Full Duplex mode results in less FPGA resources being used
Host Processor Interface Signals
STB_I	I	High	Strobe signal. When asserted, indicates the start of a valid Wishbone data transfer cycle
CYC_I	I	High	Cycle signal. When asserted, indicates the start of a valid Wishbone cycle
ACK_O	O	High	Standard Wishbone device acknowledgement signal. When this signal goes high, the Controller (Wishbone Slave) has finished execution of the requested action and the current bus cycle is terminated
ADR_I	I	2	Address bus, used to select an internal register of the device for writing to/reading from
DAT_O	O	8	Data to be sent to host processor
DAT_I	I	8	Data received from host processor
WE_I	I	Level	Write enable signal. Used to indicate whether the current local bus cycle is a Read or Write cycle: 0 = Read 1 = Write
INT_O	O	High	Interrupt signal. When the corresponding interrupt bits are enabled in the IE register, this signal is used to alert the processor that: the Transmitter has completed transmission of a frame and is ready to transmit the next frame (provided `itx` bit is set (IE.0)) reception of a frame has completed and the Receive Buffer contains valid data to be read (provided `irx` bit is set (IE.1))
Media Independent Interface (MII) Interface Signals
PHY_TXD	O	4	Data to be transmitted to the PHY
PHY_TXEN	O	High	Transmit data enable. This signal goes High when transmitting data to the PHY
PHY_TXC	I	Rise	Transmit clock. Used to clock the data that is transmitted to the PHY
PHY_RXD	I	4	Data received from the PHY
PHY_RXDV	I	High	Receive Data Valid signal. This signal goes High if data on the PHY_RXD bus is valid
PHY_RXER	I	High	Receive Error signal. This signal goes High if the PHY detects a receive error
PHY_RXC	I	Rise	Receive clock. Used to clock the data received from the PHY into the Controller
PHY_COL	I	High	Used to flag the detection of a collision
PHY_CRS	I	High	Carrier Sense signal. This signal goes high if the carrier is detected at the network side of the PHY
PHY_RESETB	O	Low	Resets the PHY. This signal is the logical NOT of the RST_I signal. Therefore resetting the Controller will cause a reset of the connected PHY device.