SNLS742A September 2023 – April 2024 DP83TC811-Q1
PRODUCTION DATA
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 |
Reserved | SGMII TX/RX Buffer Half-Full Threshold | RGMII RX Clock Internal Delay | RGMII TX Clock Internal Delay | Reserved | RGMII Mode | Reserved | |
RO-0 | RW-0 | RW/Strap | RW/Strap | RW-0 | RW/Strap | RW-0 | |
7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Clock Select | Reserved | RMII Mode | RMII Revision Select | RMII Overflow Status | RMII Underflow Status | RMII Receive Elasticity Buffer Size | |
RW/Strap | RW-1 | RW/Strap | RW-0 | RO/COR-0 | RO/COR-0 | RW-01 |
BIT | FIELD | TYPE | DEFAULT | DESCRIPTION |
---|---|---|---|---|
15 | Reserved | RO | 0 | Reserved |
14:13 | SGMII TX/RX Buffer Half-Full Threshold | RW | 10 | SGMII Buffer Half-Full Threshold: 00 = 5-bit 01 = 2-bit 10 = 6-bit 11 = 10-bit |
12 | RGMII RX Clock Internal Delay | RW | Strap | RGMII RX Clock Internal Delay: 1 = Receive path internal clock delay is enabled 0 = Receive path internal clock delay is disabled Note: When enabled, receive path internal clock (RX_CLK) is delayed by 2ns relative to receive data. When disabled, data and clock are in align mode. |
11 | RGMII TX Clock Internal Delay | RW | Strap | RGMII TX Clock Internal Delay: 1 = Transmit path internal clock delay is enabled 0 = Transmit path internal clock delay is disabled Note: When enabled, transmit path internal clock (TX_CLK) is delayed by 2ns relative to transmit data. When disabled, data and clock are in align mode. |
10 | Reserved | RW | 0 | Reserved |
9 | RGMII Mode | RW | Strap | RGMII Mode Enable: 1 = Enable RGMII mode of operation 0 = Mode determined by Bit[5] |
8 | Reserved | RW | 0 | Reserved |
7 | Clock Select | RW | Strap | Reference Clock Select: Strap determines the clock reference requirement. 1 = 50MHz clock reference, CMOS-level oscillator 0 = 25MHz clock reference, crystal or CMOS-level oscillator |
6 | Reserved | RW | 1 | Reserved |
5 | RMII Mode | RW | Strap | RMII Mode Enable: 1 = Enable RMII mode of operation 0 = Enable MII mode of operation |
4 | RMII Revision Select | RW | 0 | RMII Revision Select: 1 = RMII Revision 1.0 0 = RMII Revision 1.2 RMII revision 1.0, CRS_DV will remain asserted until final data is transferred. CRS_DV will not toggle at the end of a packet. RMII revision 1.2, CRS_DV will toggle at the end of a packet to indicate de-assertion of CRS. |
3 | RMII Overflow Status | RO, COR | 0 | RX FIFO Overflow Status: 1 = Normal 0 = Overflow detected |
2 | RMII Underflow Status | RO, COR | 0 | RX FIFO Underflow Status: 1 = Normal 0 = Underflow detected |
1:0 | RMII Receive Elasticity Buffer Size | RW | 01 | Receive Elasticity Buffer Size: This field controls the Receive Elasticity Buffer which allows for frequency variation tolerance between the 50MHz RMII clock and the recovered data. The following values indicate the tolerance in bits for a single packet. The minimum setting allows for standard Ethernet frame sizes at ±100ppm accuracy. 00 = 5-bit tolerance (up to 8750 byte packets) 01 = 2-bit tolerance (up to 1250 byte packets) 10 = 3-bit tolerance (up to 3750 byte packets) 11 = 4-bit tolerance (up to 6250 byte packets) |