Rev. 1.10
36
November 26, 2019
Rev. 1.10
37
November 26, 2019
HT68FB240
USB Low Speed Flash MCU
SYSC Register
Bit
7
6
5
4
3
2
1
0
Name
CLK_ADJ
—
—
—
—
—
—
—
R/W
R/W
—
—
—
—
—
—
—
POR
1
—
—
—
—
—
—
—
Bit 7
CLK_ADJ:
Automatic Clock
a
djusts function
0: disable
1: enable
(default)
Note that if the user selects the HIRC as the system clock, the CLK_ADJ bit must be
set to "1" to adjust the clock frequency automatically.
Bit 6~0
Unimplemented, read as "0"
UCC Register
Bit
7
6
5
4
3
2
1
0
Name
Rctrl
SYSCLK
—
SUSP2 USBCKEN
—
EPS1
EPS0
R/W
R/W
R/W
—
R/W
R/W
—
R/W
R/W
POR
0
0
—
0
0
—
0
0
Bit 7
Rctrl:
7.5kΩ resistor between UDN and UBUS control bit
Described
elsewhere
Bit 6
SYSCLK:
Specify MCU oscillator frequency indication bit
0: 12MHz
1: 6MHz
Bit 5 U
nimplemented, read as "0"
Bit 4
SUSP2:
Reduce power consumption in suspend mode control bit
Described
elsewhere
Bit 3
USBCKEN:
USB clock control bit
0: disable
1: enable
Bit 2 U
nimplemented, read as "0"
Bit 1~0
EPS1, EPS0:
Accessing endpoint FIFO selection
Described
elsewhere
SYSCLK
6MHz
12MHz
USBCKEN
USB
SIE
f
H
MUX
(See Table)
HIRC
1/2
SYSCLK
f
H
0
12MHz
1
6MHz
High frequency system clock f
H
configure