SAM3A4C Atmel Corporation, SAM3A4C Datasheet - Page 1283

• Manufacturer Part Number: SAM3A4C
• Manufacturer: Atmel Corporation

41.6.1
Name:
Address:
Access:
• LB: LoopBack
Asserts the loopback signal to the PHY.
• LLB: Loopback local
Connects txd to rxd, tx_en to rx_dv, forces full duplex and drives rx_clk and tx_clk with pclk divided by 4.
rx_clk and tx_clk may glitch as the EMAC is switched into and out of internal loop back. It is important that receive
and transmit circuits have already been disabled when making the switch into and out of internal loop back.
• RE: Receive enable
When set, enables the EMAC to receive data. When reset, frame reception stops immediately and the receive FIFO is
cleared. The receive queue pointer register is unaffected.
• TE: Transmit enable
When set, enables the Ethernet transmitter to send data. When reset transmission, stops immediately, the transmit FIFO
and control registers are cleared and the transmit queue pointer register resets to point to the start of the transmit descrip-
tor list.
• MPE: Management port enable
Set to one to enable the management port. When zero, forces MDIO to high impedance state and MDC low.
• CLRSTAT: Clear statistics registers
This bit is write only. Writing a one clears the statistics registers.
• INCSTAT: Increment statistics registers
This bit is write only. Writing a one increments all the statistics registers by one for test purposes.
• WESTAT: Write enable for statistics registers
Setting this bit to one makes the statistics registers writable for functional test purposes.
• BP: Back pressure
If set in half duplex mode, forces collisions on all received frames.
11057A–ATARM–17-Feb-12
11057A–ATARM–17-Feb-12
WESTAT
31
23
15
–
–
–
7
Network Control Register
EMAC_NCR
0x400B0000
Read-write
INCSTAT
30
22
14
–
–
–
6
CLRSTAT
29
21
13
–
–
–
5
MPE
28
20
12
–
–
–
4
TE
27
19
11
–
–
–
3
THALT
RE
26
18
10
–
–
2
TSTART
LLB
25
17
–
–
9
1
SAM3X/A
SAM3X/A
BP
LB
24
16
–
–
8
0
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