M30245_06 Datasheet, PDF (144/367 Pages) Renesas Technology Corp – RENESAS 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/20 SERIES

M30245 Group
2. USB function
(6) Device State
The device has states and, transits between the states. The M30245 group does not execute state
transition on the hardware. Control it by the software based on requests of the related USB interrupt
request. The device state transition is shown in Figure 2.8.7.
A series of processes from bus connection to configuration is called “emulation”. Each state is ex-
plained as follows:
➀Connection State:
This is the state which the device has been connected to the bus.
➁Powered State:
This is the state where the hub has been completed the configuration and has been supplied power
to the bus.
➂Default State:
This is the state where the reset signal has been received from the host CPU. It is responded as
default address (0). This is the unconfigured state (configuration 0).
➃Address State:
This is the state which the SET_ADDRESS standard device request has been received and a device
address other than “0” has been assigned. This is the unconfigured state (Configuration 0).
➄Configured State
This is the state which endpoint 0 has been received the SET_CONFIGURATION standard device
request and the device has been configured.
➅Suspend State
This is the state which inactive state followed 3ms or more.
If a bus active has been detected, the state shifts to the former one. In the M30245 group, when a bus
reset is detected in suspend state, detects bus active and shifts to the former state, then, detects the
bus reset.
(7) USB Related Registers Memory Mapping
The USB related registers memory mapping is shown in Figure 2.8.8. The list of USB related registers
items is shown in Table 2.8.2.
Rev.2.00 Oct 16, 2006 page 135 of 354
REJ09B0340-0200