mcf54455 Freescale Semiconductor, Inc, mcf54455 Datasheet - Page 34

• Manufacturer Part Number: mcf54455
• Description: 32-bit Microprocessor With Usb On-the-go, Ethernet, Pci, Ddr2/ddr Controller And Encryption
• Manufacturer: Freescale Semiconductor, Inc

Electrical Characteristics
5.13
The following timing specs are defined at the chip I/O pin and must be translated appropriately to arrive at timing
specs/constraints for the physical interface.
5.13.1
The following timing specs meet the requirements for MII and 7-Wire style interfaces for a range of transceiver devices.
34
1
In MII mode, n = 3; In RMII mode, n = 1
Num
E1
E2
E3
E4
1
2
3
I2C_SDA
—
I2C_SCL
Num
Output numbers depend on the value programmed into the IFDR; an IFDR programmed with the maximum
frequency (IFDR = 0x20) results in minimum output timings as shown in
designed to scale the actual data transition time to move it to the middle of the SCL low period. The actual
position is affected by the prescale and division values programmed into the IFDR. However, the numbers
given in
Because I2C_SCL and I2C_SDA are open-collector-type outputs, which the processor can only actively drive
low, the time I2C_SCL or I2C_SDA take to reach a high level depends on external signal capacitance and
pull-up resistor values.
Specified at a nominal 50-pF load.
I6
I7
I8
I9
Fast Ethernet Timing Specifications
1
1
1
1
Receive Signal Timing Specifications
RXCLK frequency
RXD[n:0], RXDV, RXER to RXCLK setup
RXCLK to RXD[n:0], RXDV, RXER hold
RXCLK pulse width high
RXCLK pulse width low
Table 19. I
Clock high time
Data setup time
Start condition setup time (for repeated start condition only)
Stop condition setup time
Table 19
I1
are minimum values.
2
Characteristic
C Output Timing Specifications between SCL and SDA (continued)
MCF5445x ColdFire
I2
Characteristic
Figure 18. I
Table 20. Receive Signal Timing
I4
1
®
2
1
Microprocessor Data Sheet, Rev. 0
C Input/Output Timings
I6
35%
35%
Min
—
5
5
MII Mode
I7
Max
65%
65%
25
—
—
Table
Min
I8
10
20
10
35%
35%
Min
2
—
4
2
RMII Mode
19. The I
I5
Max
I3
—
—
—
—
Max
65%
65%
50
—
—
2
C interface is
Freescale Semiconductor
RXCLK period
RXCLK period
Units
t
t
t
t
SYS
SYS
SYS
SYS
MHz
Unit
ns
ns
I9