Motorola MCF5282 MIB Control Register Mibc, Programming Examples for Mscr, Mibdisable Mibidle

Models: MCF5282 MCF5281

1 816
Download 816 pages 28.97 Kb
Page 388
Image 388

Programming Model

If the system clock is 25 MHz, programming this register to 0x0000_0005 will result in an EMDC frequency of 25 MHz * 1/10 = 2.5 MHz. A table showing optimum values for MII_SPEED as a function of system clock frequency is provided below.

Table 17-19. Programming Examples for MSCR

System Clock Frequency

MII_SPEED (field in reg)

EMDC frequency

 

 

 

25 MHz

0x5

2.5 MHz

 

 

 

33 MHz

0x7

2.36 MHz

 

 

 

40 MHz

0x8

2.5 MHz

 

 

 

50 MHz

0xA

2.5 MHz

 

 

 

66 MHz

0xD

2.5 MHz

 

 

 

17.5.4.8 MIB Control Register (MIBC)

The MIBC is a read/write register used to provide control of and to observe the state of the MIB block. This register is accessed by user software if there is a need to disable the MIB block operation. For example, in order to clear all MIB counters in RAM the user should disable the MIB block, then clear all the MIB RAM locations, then enable the MIB block. The MIB_DISABLE bit is reset to 1. See Table 17-11for the locations of the MIB counters.

31

30

16

Field

MIB_DISABLE

MIB_IDLE

 

 

 

 

Reset

 

 

1100_0000_000_000

 

 

 

 

R/W

 

 

R/W

 

 

 

 

15

 

0

Field

Reset

R/W Address

0000_0000_0000_0000

R/W

IPSBAR + 0x1064

Figure 17-11. MIB Control Register (MIBC)

Table 17-20. MIBC Field Descriptions

Bits

Name

Description

 

 

 

31

MIB_DISABLE

A read/write control bit. If set, the MIB logic will halt and not update

 

 

any MIB counters.

 

 

 

30

MIB_IDLE

A read-only status bit. If set the MIB block is not currently updating

 

 

any MIB counters.

 

 

 

29–0

Reserved.

 

 

 

17-32

MCF5282 User’s Manual

MOTOROLA

Page 388
Image 388
Motorola MCF5282, MCF5281 user manual MIB Control Register Mibc, Programming Examples for Mscr, Mibdisable Mibidle