HT82A520R HOLTEK [Holtek Semiconductor Inc], HT82A520R Datasheet - Page 47

• Manufacturer Part Number: HT82A520R
• Description: Full Speed USB 8-Bit OTP MCU with SPI
• Manufacturer: HOLTEK [Holtek Semiconductor Inc]

There is a system clock control register to select the clock used in the MCU. This register consists of a USB clock con-
trol bit, USBCKEN, a second suspend mode control bit, SUSP2, and a system clock selection bit, SYSCLK.
The endpoint selection is determined by EPS2, EPS1 and EPS0.
The AWR register contains the current address and a remote wake up function control bit. The initial value of AWR is
stage has finished.
The STALL register shows if the corresponding endpoint has worked properly or not. As soon as endpoint improper op-
eration occurs, the related bit in the STALL register has to be set high. The STALL register bits will be cleared by a USB
reset signal and a setup token event.
Rev.1.00
00H . The address value extracted from the USB command has not to be loaded into this register until the SETUP
Bit No.
Bit No.
Bit No.
0~3
4~7
1~7
0
1
2
3
4
5
6
7
0
AD0~AD6
FSYS16MHz
STL0~
STL3
USBCKEN
Label
WKEN
Label
SYSCLK
SUSP2
RCTRL
Label
EPS0
EPS1
EPS2
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Set by the users when related USB endpoints were stalled. Cleared by a USB reset.
The STL0 is also cleared by a Setup Token event. Default value is 0000 .
Unused bit, read as 0
USB remote-wake-up enable/disable (1/0). Default value is 0 .
USB device address. Default value is 0000000 .
Accessing endpoint FIFO selection. Default value is 000 .
EPS2, EPS1, EPS0:
000: Select endpoint 0 FIFO (control)
001: Select endpoint 1 FIFO
010: Select endpoint 2 FIFO
011: Select endpoint 3 FIFO
If the selected endpoints do not exist, the related functions will be absent.
USB clock control bit. When this bit is set to 1 , it indicates that the USB clock
is enabled. Otherwise, the USB clock is turned-off. Default value is 0 .
This bit is used for reducing power consumption in suspend mode.
In normal mode, clean this bit to 0 . (default)
In halt mode, set this bit to 1 for reducing power consumption.
This bit is used to define if the MCU system clock comes form an external
OSC or comes from the PLL output 16MHz clock.
0: system clock sourced from OSC. (default)
1: system clock sourced from the PLL output 16MHz.
This bit is used to specify the MCU system clock oscillator frequency.
For a 6MHz crystal oscillator or resonator, set this bit to 1 .
For a 12MHz crystal oscillator or resonator, clear this bit to 0 . (default)
This bit is used to control whether there is 7.5k
Vbus.
0: no 7.5k between D+ and Vbus (default)
1: has 7.5k between D+ and Vbus
STALL Register
AWR Register
UCC Register
47
Function
Function
Function
HT82A520R/HT82A620R
resistor between D+ and
October 23, 2009