HT82A832R_07 Datasheet, PDF (18/51 Pages) Holtek Semiconductor Inc – USB Audio MCU

HT82A832R
options). Each bit of these input/output latches can be
set or cleared by ²SET [m].i² and ²CLR [m].i² (m=12H,
14H, 16H ) instructions.
Some instructions first input data and then follow the
output operations. For example, ²SET [m].i², ²CLR
[m].i², ²CPL [m]², ²CPLA [m]² read the entire port states
into the CPU, execute the defined operations
(bit-operation), and then write the results back to the
latches or the accumulator.
Each line of port A has the capability of waking-up the
device.
Low Voltage Reset - LVR (by Configuration Option)
The LVR option is 3.0V.
The microcontroller provides a low voltage reset circuit
in order to monitor the supply voltage of the device. If the
supply voltage of the device is within the range
0.9V~V_LVR, the LVR will automatically reset the device
internally.
The LVR includes the following specifications:
· The low voltage (0.9V~V_LVR) condition has to remain
in its condition for a time exceeding 1ms. If the low
voltage state does not exceed 1ms, the LVR will ig-
nore it and will not perform a reset function.
· The LVR uses the ²OR² function with the external
RESET signal to perform a chip reset.
Suspend Wake-Up and Remote Wake-Up
If there is no signal on the USB bus for over 3ms, the
HT82A832R will go into a suspend mode. The Suspend
line (bit 0 of the USC) will be set to ²1² and a USB
interrupt is triggered to indicate that the HT82A832R
should jump to the suspend state to meet the
requirements of the USB suspend current spec.
In order to meet the requirements of the suspend
current, the firmware should disable the USB clock by
clearing USBCKEN (bit3 of UCC) to ²0².
Also the user can further decrease the suspend current
by setting SUSP2 (bit4 of the UCC).
When the resume signal is sent out by the host, the
HT82A832R will be woken up by the USB interrupt and
the Resume line (bit 3 of USC) will be set. In order to
make the HT82A832R work properly, the firmware must
set USBCKEN (bit 3 of UCC) to ²1² and clear SUSP2
(bit4 of the UCC). Since the Resume signal will be
cleared before the Idle signal is sent out by the host and
the Suspend line (bit 0 of USC) will go to ²0². So when
the MCU is detecting the Suspend line (bit0 of USC), the
condition of the Resume line should be noted and taken
into consideration.
The following is the timing diagram:
SUSPEND
U S B R e s u m e S ig n a l
U S B _ IN T
The device with remote wake up function can wake-up
the USB Host by sending a wake-up pulse through
RMWK (bit 1 of USC). Once the USB Host receives the
wake-up signal from the HT82A832R, it will send a
Resume signal to the device. The timing is as follows:
SUSPEND
RM W K
M in . 1
U S B C LK
U S B R e s u m e S ig n a l
M in . 2 .5 m s
U S B _ IN T
USB Interface
The HT82A832R device has 5 Endpoints (EP0~EP4).
EP0 supports Control transfer. EP1 and EP4 support
Interrupt transfer. EP2 supports Isochronous out
transfer. EP3 supports Isochronous in transfer.
These registers, including USC (20H), USR (21H), UCC
(22H), AWR (23H), STALL (24H), SIES (25H), MISC
(26H), FIFO0 (28H), FIFO1 (29H), FIFO2 (2AH), FIFO3
(2BH), FIFO4 (2CH) are used for the USB function.
The FIFO size of each FIFO is 8 bytes (FIFO0), 8 bytes
(FIFO1), 384 bytes (FIFO2), 32 bytes (FIFO3), 32 bytes
(FIFO4). The total is 464 bytes.
URD (bit7 of USC) is the USB reset signal control
function definition bit.
Rev. 1.10
18
June 15, 2007