Cypress EZ-USB FX3 User Manual

EZ-USB FX3 Technical Reference Manual, Document Number: 001-76074 Rev. *F 393
DEV_FRAMECNT
0xE0031404
10.11.2 DEV_FRAMECNT
FRAMECNT Register
USB SOF and uSOF frame counts USB.
13:3 FRAMECNT[10:0] Every millisecond the host sends a SOF token indicating “Start Of Frame,” along with an 11-bit incre-
menting frame count. FX3 copies the frame count into these registers at every SOF. One use of the
frame count is to respond to the USB SYNC_FRAME Request. If the USB core detects a missing or
garbled SOF, it generates an internal SOF and increments USBFRAMEL-USBRAMEH.
2:0 MICROFRAME[2:0] MICROFRAME contains a count 0-7 which indicates which of the eight 125-microsecond microf-
rames last occurred. This register is active only when FX3 is operating at High Speed (480 Mbps).
DEV_FRAMECNT FRAMECNT Register 0xE0031404
b31 b30 b29 b28 b27 b26 b25 b24
DEV_FRAMECNT FRAMECNT Register
b23 b22 b21 b20 b19 b18 b17 b16
DEV_FRAMECNT FRAMECNT Register
b15 b14 b13 b12 b11 b10 b9 b8
FRAMECNT[10:5]
RRRRRR
R/W R/W R/W R/W R/W R/W
N/A N/A N/A N/A N/A N/A
DEV_FRAMECNT FRAMECNT Register
b7 b6 b5 b4 b3 b2 b1 b0
FRAMECNT[4:0] MICROFRAME[2:0]
RRRRRRRR
R/W R/W R/W R/W R/W R/W R/W R/W
N/A N/A N/A N/A N/A N/A N/A N/A
Bit Name Description

Cypress EZ-USB FX3 Specifications

General

Brand	Cypress
Model	EZ-USB FX3
Category	Controller
Language	English