SM320C6455-EP

FIXED-POINT DIGITAL SIGNAL PROCESSOR

www.ti.com

SPRS462B – SEPTEMBER 2007 – REVISED JANUARY 2008

7.14.3.2 EMAC RMII Electrical Data/Timing

The RMREFCLK pin is used to source a clock to the EMAC when it is configured for RMII operation. The RMREFCLK frequency should be 50 MHz ±50 PPM with a duty cycle between 35% and 65%, inclusive.

Table 7-81. Timing Requirements for RMREFCLK - RMII Operation (see Figure 7-65)

 

 

 

-720

 

 

 

 

 

-850

 

 

NO.

 

PARAMETER

A-1000/-1000

UNIT

 

 

 

-1200

 

 

 

 

 

MIN

MAX

 

1

tw(RMREFCLKH)

Pulse duration, RMREFCLK high

7

13

ns

2

tw(RMREFCLKL)

Pulse duration, RMREFCLK low

7

13

ns

3

tt(RMREFCLK)

Transition time, RMREFCLK

 

2

ns

3

1

RMREFCLK (Input)

2

3

Figure 7-65. RMREFCLK Timing

Table 7-82. Switching Characteristics Over Recommended Operating Conditions for EMAC RMII Transmit

10/100 Mbit/s(1) (see Figure 7-66)

 

 

 

-720

 

 

 

 

 

-850

 

 

NO.

 

PARAMETER

A-1000/-1000

 

UNIT

 

-1200

 

 

 

 

1000 Mbps

 

 

 

 

 

MIN

MAX

 

1

td(RMREFCLKH-MTXD)

Delay time, RMREFCLK high to transmit selected signals valid

3

10

ns

(1)For RMII, transmit selected signals include: MTXD[1:0] and MTXEN.

1

RMREFCLK (Input)

MTXD1-MTXD0,

MTXEN (Outputs)

Figure 7-66. EMAC Transmit Interface Timing [RMII Operation]

Submit Documentation Feedback

C64x+ Peripheral Information and Electrical Specifications

211

Page 211
Image 211
Texas Instruments SM320C6455-EP manual Emac Rmii Electrical Data/Timing, Rmrefclk Input