HT82B42R_14 Datasheet, PDF (51/84 Pages) Holtek Semiconductor Inc – I/O MCU with USB Interface

HT82B42R/HT82B42RE
I/O MCU with USB Interface
There is a system clock control register implement to select the clock used in the MCU. This register
consisters of the USB clock sontrol bit, USBCKEN, second suspend mode control bit, SUSP2, and
a system colck selection bit, SYSCLK. The PS2 mode indicate bit, PS2_flag, and a system clock
adjust control bit, CLK_adj.
SCC Register
Bit
7
6
5
4
3
2
1
0
Name CLK_adj SYSCLK PS2_flag SUSP2 USBCKEN ―
―
―
R/W
R/W
R/W
R/W
R/W
R/W
―
―
―
POR
0
0
0
0
0
―
―
―
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2~0
CLK_adj: USB mode system clock adjustment
0: enable (default)
1: disable
This bit is used to adjust the system clock for the USB mode for temperature changes.
In the Power-down Mode this bit should be set high to reduce power consumption.
SYSCLK: Specify MCU oscillator frequency indication bit
0: 12MHz crystal oscillator or resonator, clear this bit to “0”
1: 6MHz crystal oscillator or resonator, set this bit to “1”
This bit is used to specify the system oscillator frequency used by the MCU. If an
Integrated 6MHz oscillator is used, this bit should be set to “1”. If an Integrated
12MHz oscillator is used, this bit should be cleared to “0” (default).
PS2_flag: PS2 mode indication bit
0: not PS2 mode
1: PS2 mode
This flag is used to indicate that the MCU is in the PS2 mode. (Bit=1)
This bit is R/W by FW and will be cleared to “0” after power-on reset. (Default="0")
SUSP2: Reduce power consumption in suspend mode control bit
0: in normal mode
1: in halt mode, set this bit to “1” for reducing power consumption
USBCKEN: USB clock control bit
0: disable
1: enable
Unimplemented
STALL and PIPE, PIPE_CTRL, Endpt_EN Registers
The PIPE register represents whether the corresponding endpoint is accessed by the host or not.
After an ACT_EN signal has been sent out, the MCU can check which endpoint had been accessed.
This register is set only after the a time when the host is accessing the corresponding endpoint.
The STALL register shows whether the corresponding endpoint works or not. As soon as the
endpoint works improperly, the corresponding bit must be set.
The PIPE_CTRL Register is used for configuring the IN (Bit=1) or OUT (Bit=0) Pipe. The default
is define IN pipe. Bit 0 (DATA0) of the PIPE_CTRL Register is used to set the data toggle of any
endpoint (except endpoint 0) using data toggles to the value DATA0. Once the user wants any
endpoint (except endpoint 0) using data toggles to the value DATA0. the user can output a LOW
pulse to this bit. The LOW pulse period must at least 10 instruction cycles.
The Endpt_EN Register is used to enable or disable the corresponding endpoint (except endpoint 0)
Enable Endpoint (Bit=1) or disable Endpoint (Bit=0)
Rev. 1.10
51
November 05, 2014