Cypress Semiconductor SL811HS Bedienungsanleitung PDF herunterladen (Seite 29)

Cypress Semiconductor Corporation

SL811HS and SL811HST: Application Notes

and specifications contained in this document are subject to change without

notice.

Date: 07/26/01

Revision: 1.21

Page: 29

The width of the SE0 in the EOP is approximately 2 * TPERIOD. The SE0 width is measured

with the same load used for maximum rise and fall times and is measured at the same level as

the differential signal crossover points of the data lines.

Program Sample 12: Hardware EOP Generation

int hw_sof()int hw_sof()

{{

... // Need USB Reset ... // Need USB Reset

SL11Wri SL11Write(cDATASet,0xe0); // Set up SOF or EOP for 1ms intervalte(cDATASet,0xe0); // Set up SOF or EOP for 1ms interval

SL11Write(cSOFcnt,0xae); // Set up frame counter SL11Write(cSOFcnt,0xae); // Set up frame counter

SL11Write(CtrlReg,05); // Enable SOF/EOP SL11Write(CtrlReg,05); // Enable SOF/EOP

SL11Write(EP0Control, 0x01); // Start SOF/EOP SL11Write(EP0Control, 0x01); // Start SOF/EOP

}}

An EOP is generated by within the SL811HS hardware; therefore, there is no need to use an

external CPU to generate an EOP when using the SL811HS. The following is a sequence

showing the SL811HS generating the EOP during Token, Data, and Handshaking phases.

Figure 6: Token Phase

SYNC IN/OUT Token EOP

Figure 7: Data Phase

SYNC Data Packet EOP

Figure 8: Handshaking phase

SYNC ACK/NAK/STALL EOP

USB Trace 4: SOF Packet

1 2 ... 24 25 26 27 28 29 30 31 32 33 34 ... 42 43

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Cypress Semiconductor SL811HS Bedienungsanleitung Seite 29