ht82a836r Holtek Semiconductor Inc., ht82a836r Datasheet - Page 41

• Manufacturer Part Number: ht82a836r
• Description: Usb Audio Mcu
• Manufacturer: Holtek Semiconductor Inc.

SETIO Register
The SETIO register is used to setup the endpoints to ei-
ther input or output pipe type. The DATA token toggle bit
is also contained within this register. Note that for USB
definition, when the host sends a set Configuration ,
the Data pipe should send DATA0, about the Data tog-
gle, first. Therefore, when the device receives a set
configuration setup command, the user needs to toggle
this bit as the following data will send DATA0 first. It is
only required to set the data pipe as an input pile or out-
put pile. The purpose of this function is to avoid the host
sending an abnormal IN or OUT token and disabling the
endpoint. All bits are read/write.
SETIO (27H) register, USB Endpoint 1~Endpoint 4 set
IN/OUT pipe register.
USB_STATE Register
This register is used to indicate the error state due to
SE0 or SE1 noise as well as the USBD- and USBD+ in-
put signals. The SE0 and SE1 bits are set by the SIE
and cleared with the program.
Rev. 1.00
USB Endpoint Setup IN/OUT Pipe Register - SETIO
USB State Register - USB-STATE
41
Suspend Wake-Up Remote Wake-Up
The device includes a Suspend mode. If there is no sig-
nal on the USB bus for over 3ms, the device will enter a
suspend mode. When this happens, the SUSPEND bit,
which is bit 0 of the USC register, will be set to 1 and a
USB interrupt will be generated to indicate that the de-
vice should jump to the suspend state to meet the re-
quirements of the USB suspend current spec. In order to
meet the requirements of the suspend current, the pro-
gram should disable the USB clock by clearing the
USBCKEN bit, which is bit3 of the UCC register, to 0 .
The suspend current can be further decreased by set-
ting the SUSP2 bit, which is bit4 of the UCC register.
When the resume signal is sent out by the host, the
HT82A836R will be woken up the by the USB interrupt
and the RESUME bit, which is bit 3 of the USC register,
will be set. In order to make the device operate correctly,
the program must set the USBCKEN bit and clear the
SUSP2 bit. Since the Resume signal will be cleared be-
fore the Idle signal is sent out by the host and the SUS-
PEND bit, will change to 0 . Therefore when the MCU
is detecting the Suspend line, the condition of the Re-
sume line should be noted and taken into consideration.
HT82A836R
March 20, 2008