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Fast Ethernet Controllers (FEC0 and FEC1)
26-21
Freescale Semiconductor
26.4.11 Transmit Control Registers (TCR0 & TCR1)
TCR
n
is read/write and configures the transmit block. This register is cleared at system reset. Bits 2 and 1
must be modified only when ECR
n
[ETHER_EN] is cleared.
5
FCE
Flow control enable. If asserted, the receiver detects PAUSE frames. Upon PAUSE frame detection, the transmitter
stops transmitting data frames for a given duration.
4
BC_REJ
Broadcast frame reject. If asserted, frames with DA (destination address) equal to FFFF_FFFF_FFFF are rejected
unless the PROM bit is set. If BC_REJ and PROM are set, frames with broadcast DA are accepted and the M
(MISS) is set in the receive buffer descriptor.
3
PROM
Promiscuous mode. All frames are accepted regardless of address matching.
2
MII_MODE
Media independent interface mode. Selects the external interface mode for transmit and receive blocks.
0 7-wire mode (used only for serial 10 Mbps)
1 MII or RMII mode as indicated by the RMII_MODE bit
1
DRT
Disable receive on transmit.
0 Receive path operates independently of transmit (use for full duplex or to monitor transmit activity in half duplex
mode).
1 Disable reception of frames while transmitting (normally used for half duplex mode).
0
LOOP
Internal loopback. If set, transmitted frames are looped back internal to the device and transmit output signals are
not asserted. The internal bus clock substitutes for the FEC
n
_TXCLK when LOOP is asserted. DRT must be set
to 0 when setting LOOP.
Address: 0xFC03_00C4 (TCR0)
0xFC03_40C4 (TCR1)
Access: User read/write
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8
7
6
5
4
3
2
1
0
R
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
RFC_
PAUSE TFC_
PAUSE
FDEN HBC GTS
W
Reset 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0
0
0
0
0
Figure 26-11. Transmit Control Register (TCR
n
)
Table 26-15. TCR Field Descriptions
Field
Description
31–5
Reserved, must be cleared.
4
RFC_PAUSE
Receive frame control pause. This read-only status bit is asserted when a full duplex flow control pause frame is
received and the transmitter pauses for the duration defined in this pause frame. This bit automatically clears
when the pause duration is complete.
3
TFC_PAUSE
Transmit frame control pause. Transmits a PAUSE frame when asserted. When this bit is set, the MAC stops
transmission of data frames after the current transmission is complete. At this time, GRA interrupt in the EIR
n
register is asserted. With transmission of data frames stopped, MAC transmits a MAC Control PAUSE frame.
Next, the MAC clears the TFC_PAUSE bit and resumes transmitting data frames. If the transmitter pauses due
to user assertion of GTS or reception of a PAUSE frame, the MAC may continue transmitting a MAC Control
PAUSE frame.
Table 26-14. RCR
n
Field Descriptions (continued)
Field
Description
Summary of Contents for MCF54455
Page 33: ...xxviii Freescale Semiconductor ...
Page 67: ...Freescale Semiconductor 1 ...
Page 125: ...Freescale Semiconductor 1 ...
Page 145: ...Enhanced Multiply Accumulate Unit EMAC 5 21 Freescale Semiconductor ...
Page 173: ...Cache 6 28 Freescale Semiconductor ...
Page 179: ...Static RAM SRAM 7 6 Freescale Semiconductor ...
Page 207: ...Power Management 9 16 Freescale Semiconductor ...
Page 323: ...Reset Controller Module 13 8 Freescale Semiconductor ...
Page 389: ...Pin Multiplexing and Control 16 44 Freescale Semiconductor ...
Page 575: ...PCI Bus Controller 22 58 Freescale Semiconductor ...
Page 600: ...Advanced Technology Attachment ATA Freescale Semiconductor 23 25 ...
Page 601: ...Freescale Semiconductor 1 ...
Page 842: ...I2 C Interface Freescale Semiconductor 33 16 ...
Page 843: ...Freescale Semiconductor 1 ...
Page 921: ...Revision History A 6 Freescale Semiconductor ...