Rev. 1.10
108
November 26, 2019
Rev. 1.10
109
November 26, 2019
HT68FB240
USB Low Speed Flash MCU
USB Interface Operation
The device has
3
Endpoints (EP0~EP
2
). EP0 supports Control transfer for Setup, IN and OUT token
respectively. EP1
and
EP
2
support Interrupt transfer. These registers, including USB_STAT, UINT,
USC, UCC, AWR, STL, SIES, MISC, UFEN, URDCT and FIFO0~FIFO2 are used for the USB
function.
EP0, EP1 and EP2
each h
ave 8
-byte FIFO size
respectively. EP0 supports DMA interface for
Co
nfigure USB descriptor. Please reference the DMA for detail description. EP0~EP2 are equiped
with independent registers and not shared with the general data memory RAM. The Serial Interface
Engine (SIE) of the device is compatible with USB 2.0 Low speed protocol.
The
URD
in the USC register is the USB reset signal control function definition bit.
USB Interface Registers
The USB interface has a series of registers associated with its operation.
USB_STAT Register
Bit
7
6
5
4
3
2
1
0
Name
PS2_CKO PS2_DAO PS2_CKI PS2_DAI
SE1
SE0
PU
ESD
R/W
W
W
R
R
R/W
R/W
R/W
R/W
POR
1
1
x
x
0
0
0
—
"x" unknown
"-" Hardware did not give ESD bit initial value in power on reset
Bit 7
PS2_CKO:
Output for driving UDP/GPIO1 pin, when work under 3D PS2 mouse
function. Default value is "1".
Bit 6
PS2_DAO:
Output for driving UDN/GPIO
0
pin, when work under 3D PS2 mouse
function. Default value is "1".
Bit 5
PS2_CKI:
UDP/GPIO
1
input.
Bit 4
PS2_DAI:
UDN/GPIO
0
input.
Bit 3
SE1:
This bit is used to indicate the SIE has detected a SE1 noise in the USB bus. This
bit is set by SIE and clear
ed
by F/W.
Bit 2
SE0:
This bit is used to indicate the SIE has detected a SE0 noise in the USB bus. This
bit is set by SIE and clear
ed
by F/W.
Bit 1
PU:
Bit1=1, UDP and UDN have a 600kΩ pull-high
.
Bit1=0, no pull-high (default on
MCU reset)
Bit 0
ESD:
This bit will set to "1" when there is ESD issue.
This bit is set by SIE and cleared by F/W.
Hardware did not give ESD bit initial value
in power on reset.