AN2131-DK001 Cypress Semiconductor Corp, AN2131-DK001 Datasheet - Page 158

• Manufacturer Part Number: AN2131-DK001
• Description: KIT EZ-USB DEVELOPMENT BOARD
• Manufacturer: Cypress Semiconductor Corp

Specifications of AN2131-DK001

• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: 428-1333

The timing choices for fast write pulses (FWR#) are shown in Figure 8-11. The 8051 can
extend the output data and widths of these pulses by setting cycle stretch values greater
than zero in the 8051 Clock Control Register CKCON (at SFR location 0x8E). The top
five waveforms show the fastest write timings, with a stretch value of 000, which per-
forms the write in eight 8051 clocks. The bottom five waveforms show the same wave-
forms with a stretch value of 001.
8.7.2 Fast Read Waveforms
The timing choices for fast read pulses (FRD#) are shown in Figure 8-12. Read Strobe
waveforms for stretch values of 000 and 001 are indicated. Although two of the read
strobe widths can be extended using stretch values greater than 000, the times that the
input data is sampled by the EZ-USB core remains the same as shown.
EZ-USB TRM v1.9
FRD#[00]
FRD#[01]
FRD#[10]
FRD#[10]
FRD#[11]
FRD#[11]
OSC24
D[7..0]
D[7..0]
D[7..0]
D[7..0]
41.66 ns
tCL
Note: If WPOL=1 the waveforms are inverted
Figure 8-12. Fast Read Timing
[nn] = RMOD1:RMOD0, RPOL=0
In
Chapter 8. EZ-USB CPU
In
In
In
stretch=000, 001
stretch=000, 001
stretch=000
stretch=001
stretch=000
stretch=001
Page 8-13