38K2 Datasheet, PDF (57/151 Pages) Renesas Technology Corp – SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER

38K2 Group
HUB FUNCTION
The 38K2 Group has a HUB Function Control Circuit (HUBFCC)
that offers easy implementation of USB-hub functions (signal re-
peat and bus state detection). This circuit is in compliance with
USB Specification Version 2.0 Full-Speed/Low-Speed Transfer
Modes (12 Mbps/1.5 Mbps, equivalent to Version 1.1).
The HUBFCC operates with two external down-ports and one in-
ternal down-port, which is utilized by the USB addresses of the
built-in peripherals, enabling management of a total of three down-
ports independently.
A dedicated circuit automatically performs the bus state change
detection and error detection needed for the sequence manage-
ment of the hub repeater circuit, data repeat function, and
down-port status management. This dedicated control circuit en-
sures the user easy development of a program or timing design.
Each down-port register can be controlled by USB commands us-
ing USB addresses for HUB functions or detecting changes in the
bus state of down-ports. The HUBFCC is also equipped with a re-
mote wakeup signal transfer function for use during global resume
as other special signals management. The HUBFCC generates an
interrupt to the CPU when detecting a down-port state change (1
vector, 10 sources).
The flexibility of the indispensable yet wide-ranging HUBFCC
structure and an external interrupt function and I/O ports imple-
mented in the standard features of this MCU enable the power
supply management essential for USB-HUB functions and also al-
low users to easily and effortlessly configure their optimum
system.
38K2 Group
CPU
USB
HUB
Internal down-
port
External down-port External down-port
(USB device)
(USB device)
Fig. 87 HUB functions
Up-port
(USB host)
Rev.3.00 Oct 15, 2006 page 57 of 147
REJ03B0193-0300