Datasheet

Table Of Contents
Fast Ethernet Controller (FEC)
Freescale Semiconductor 17-11
17.4.4 Receive Descriptor Active Register (RDAR)
RDAR is a command register, written by the user, indicating the receive descriptor ring is updated (the
driver produced empty receive buffers with the empty bit set).
When the register is written, the RDAR bit is set. This is independent of the data actually written by the
user. When set, the FEC polls the receive descriptor ring and processes receive frames (provided
ECR[ETHER_EN] is also set). After the FEC polls a receive descriptor whose empty bit is not set, FEC
clears the RDAR bit and ceases receive descriptor ring polling until the user sets the bit again, signifying
that additional descriptors are placed into the receive descriptor ring.
The RDAR register is cleared at reset and when ECR[ETHER_EN] is cleared.
IPSBAR
Offset:
0x1008 Access: User read/write
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
R
HB
ERR
BABR BABT GRA TXF TXB RXF RXB MII
EB
ERR
LC RL UN
000
W
Reset0000000000000000
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
R 0000000000 000000
W
Reset0000000000000000
Figure 17-3. Ethernet Interrupt Mask Register (EIMR)
Table 17-6. EIMR Field Descriptions
Field Description
31–19
See
Figure 17-3
and Table 17-5
Interrupt mask. Each bit corresponds to an interrupt source defined by the EIR register. The corresponding
EIMR bit determines whether an interrupt condition can generate an interrupt. At every processor clock, the
EIR samples the signal generated by the interrupting source. The corresponding EIR bit reflects the state of
the interrupt signal even if the corresponding EIMR bit is set.
0 The corresponding interrupt source is masked.
1 The corresponding interrupt source is not masked.
18–0 Reserved, must be cleared.
IPSBAR
Offset:
0x1010 Access: User read/write
31302928272625 24 23222120191817161514131211109876543210
R0000000
RDAR
000000 0 00000000000000000
W
Reset0000000 0 000000000000000000000000
Figure 17-4. Receive Descriptor Active Register (RDAR)
MCF5282 and MCF5216 ColdFire Microcontroller User’s Manual, Rev. 3