Datasheet

39.6.38 Host Frame Number Register

Name: USBHS_HSTFNUM

Offset: 0x0420

Reset: 0x00000000

Property: Read/Write

Bit 31 30 29 28 27 26 25 24

Access

Reset

Bit 23 22 21 20 19 18 17 16

FLENHIGH[7:0]

Access

Reset 0 0 0 0 0 0 0 0

Bit 15 14 13 12 11 10 9 8

FNUM[10:5]

Access

Reset 0 0 0 0 0 0

Bit 7 6 5 4 3 2 1 0

FNUM[4:0] MFNUM[2:0]

Access

Reset 0 0 0 0 0 0 0 0

Bits 23:16 – FLENHIGH[7:0] Frame Length

In High-speed mode, this field contains the 8 high-order bits of the 16-bit internal frame counter (at 30

MHz, the

counter length is 3750 to ensure a SOF generation every 125 μs).

Bits 13:3 – FNUM[10:0] Frame Number

This field contains the current SOF number.

This field can be written. In this case, the MFNUM field is reset to zero.

Bits 2:0 – MFNUM[2:0] Micro Frame Number

This field contains the current microframe number (can vary from 0 to 7), updated every 125 μs.

When operating in Full-speed mode, this field is tied to zero.

SAM E70/S70/V70/V71 Family

USB High-Speed Interface (USBHS)

echnology Inc.

Datasheet

DS60001527D-page 872