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Ethernet Module
MCF5272 ColdFire
®
Integrated Microprocessor User’s Manual, Rev. 3
11-22
Freescale Semiconductor
11.5.12 FIFO Transmit Start Register (TFSR)
The TFSR register,
, can be programmed by the user to indicate the starting address of the
transmit FIFO. Usually there is no need to program TFSR. For optimal RAM allocation, do not program
TFSR to a value less than its reset value. The value in this register must be added to MBAR + 0x800 to
determine the absolute address.
The TFSR register is reset to the first available RAM address.
31
16
Field
—
Reset
0000_0000_0000_0000
R/W
Read/Write
15
11
10
9
2
1
0
Field
—
1
X_FSTART
—
Reset
0000_0
1
0001_1000
00
R/W
Read/Write
Addr
MBAR + 0x8EC
Figure 11-16. FIFO Transmit Start Register (TFSR)
Table 11-19. TFSR Field Descriptions
Bits
Name
Description
31–11
—
Reserved, should be cleared.
10
—
Reserved, should be set.
9–2
X_FSTART
Transmit FIFO starting address. Address of first transmit FIFO location.
1–0
—
Reserved, should be cleared.