Car Stereo System - Car Radio Digital Signal Processor User Manual

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7.14.3.2 EMAC RMII Electrical Data/Timing
RMREFCLK
(Input)
1
2
3
3
1
RMREFCLK
(Input)
MTXD1-MTXD0,
MTXEN (Outputs)
SM320C6455-EP
FIXED-POINT DIGITAL SIGNAL PROCESSOR
SPRS462B – SEPTEMBER 2007 – REVISED JANUARY 2008
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
A-1000/-1000
NO. PARAMETER UNIT
-1200
MIN MAX
1 t
w(RMREFCLKH)
Pulse duration, RMREFCLK high 7 13 ns
2 t
w(RMREFCLKL)
Pulse duration, RMREFCLK low 7 13 ns
3 t
t(RMREFCLK)
Transition time, RMREFCLK 2 ns
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
A-1000/-1000
NO. PARAMETER UNIT
-1200
1000 Mbps
MIN MAX
1 t
d(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.
Figure 7-66. EMAC Transmit Interface Timing [RMII Operation]
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