MCF5272VF66 Freescale, MCF5272VF66 Datasheet - Page 250

• Manufacturer Part Number: MCF5272VF66
• Manufacturer: Freescale

Specifications of MCF5272VF66

• Family Name: MCF5xxx
• Device Core: ColdFire
• Device Core Size: 32b
• Frequency (max): 66MHz
• Instruction Set Architecture: RISC
• Supply Voltage 1 (typ): 3.3V
• Operating Temp Range: 0C to 70C
• Operating Temperature Classification: Commercial
• Mounting: Surface Mount
• Pin Count: 196
• Package Type: MA-BGA
• Lead Free Status / RoHS Status: Not Compliant

Ethernet Module
11.5.21 Receive Buffer Size Register (EMRBR)
The EMRBR register dictates the maximum size of all receive buffers. Note that because receive frames
are truncated at 2k-1 bytes, only bits 10–4 are used. This value should take into consideration that the
receive CRC is always written into the last receive buffer. To allow one maximum size frame per buffer,
R_BUFF_SIZE must be set to MAX_FL or larger. The R_BUFF_SIZE must be evenly divisible by 16. To
insure this, bits 3–0 are forced low. To minimize bus utilization (descriptor fetches), it is recommended
that R_BUFF_SIZE be at least 256 bytes.
This register,
11-32
31–11
10–4
Bits
3–0
Reset
Reset
Field
Field
Addr
R/W
R/W
31
15
R_BUFF_SIZE
Figure
Name
—
—
11-26, is not reset and must be initialized by the user prior to operation.
0000_0
MCF5272 ColdFire
—
Reserved, should be cleared.
Reserved, should be cleared.
Receive buffer size.
Figure 11-26. Receive Buffer Size (EMRBR)
Table 11-29. EMRBR Field Descriptions
11
®
Integrated Microprocessor User’s Manual, Rev. 3
10
0000_0000_0000_0000
MBAR + 0xC18
Read/Write
Read/Write
R_BUFF_SIZE
—
Description
4
3
Freescale Semiconductor
0000
—
16
0