HT82K94E/HT82K94A

Rev. 2.40

23

November 5, 2014

System Clock Control Register

This register is designed to control the system clock and make the device to meet USB 500

mA suspend current spec. as

well as a LVD indicator.

Since the device can operate at 6MHz or 12MHz in USB mode, so in order to make SIE work properly, there should has

a SYSCLK bit to indicate what system frequency is working.

The USBCKEN bit is used to turn-off or turn-on the SIE system clock to meet the USB 500

mA suspend current. For

normal operation, this bit must be 1. Otherwise, the SIE cannot detect the USB signal.

PS2_flag bit is only a bit for firmware to store the PS2 mode data. This bit only clear to zero by hardware after power-on

reset. SUSPEND2 bit is used to second suspend mode.

Bit No.

Label

R/W

Function

0, 2

¾¾

Undefined, should be cleared to

²0²

1

OSC_ctrl

R/W

1: High driver of oscillator circuit for low voltage

0: normal driver of oscillator circuit

3

USBCKEN

R/W

USB clock control bit. When this bit is set to

²1², it indicates that the USB clock is en-

abled. Otherwise, the USB clock is turned-off. (Default=

²0²)

4

SUSPEND2

R/W

This bit is used to reduce power consumption in the suspend mode. In the normal

mode this bit must be cleared to zero(Default=

²0²). In the HALT mode this bit should

be set high to reduce power consumption and LVR with no function. In the USB

mode this bit cannot be set high.

5

PS2_flag

R/W

This flag is used to show the MCU is under PS2 mode. (Bit=1)

This bit is R/W by FW and will be cleared to

²0² after power-on reset. (Default=²0²)

6

SYSCLK

R/W

This bit is used to specify the system oscillator frequency used by the MCU. If a

6MHz crystal oscillator or resonator is used, this bit should be set to

²1². If a 12MHz

crystal oscillator or resonator is used, this bit should be cleared to

²0² (default).

7

LVD

R

1: battery voltage low

0: battery voltage high

SCC (1EH) Register

Table High Byte Pointer for Current Table Read TBHP (Address 0X1F)

Register

Bits

Labels

Read/Write

Option

Functions

(0X1F)

4~0

PGC4~PGC0

R/W

¾

Store current table read bit12~bit8 data