HT82J97A_08 HOLTEK [Holtek Semiconductor Inc], HT82J97A_08 Datasheet - Page 19

• Manufacturer Part Number: HT82J97A_08
• Description: USB Joystick Encoder 8-Bit MCU
• Manufacturer: HOLTEK [Holtek Semiconductor Inc]

There are some timing constrains and usages illustrated here. By setting the MISC register, the MCU can perform read-
ing, writing and clearing actions. There are some examples shown in the following table for endpoint FIFO reading, writ-
ing and clearing.
Note: *: There are 2 s gap existing between 2 reading actions or between 2 writing actions
USB Active Pipe Timing
The USB active pipe accessed by the host cannot be used by the MCU simultaneously. When the host finishes its work,
the signal, a USB_INT will be produced to tell the MCU that the pipe can be used and the acted pipe No. will be shown
in the signal, ACT_PIPE as well. The timing is illustrated in the figure below.
Suspend Wake-Up and Remote Wake-Up
If there is no signal on the USB bus for over 3ms, the
HT82J97E/HT82J97A will go into a suspend mode. The
Suspend line (bit 0 of the USC) will be set to 1 and a
USB interrupt is triggered to indicate that the
HT82J97E/HT82J97A should jump to the suspend state
to meet the 500 A USB suspend current spec.
In order to meet the 500 A suspend current, the pro-
grammer should disable the USB clock by clearing the
USBCKEN (bit3 of the SCC) to 0 . The suspend cur-
rent is 400 A.
The user can also further decrease the suspend current
to 250 A by setting the SUSP2 (bit4 of the SCC). But if
the SUSP2 is set, the user has to make sure not to en-
a b l e t h e LV R O P T o p t i o n , o t h e r w i s e t h e
HT82J97E/HT82J97A will be reset.
When the resume signal is sent out by the host, the
HT82J97E/HT82J97A will wake-up the MCU by USB in-
Rev. 1.60
Read FIFO0 sequence
Write FIFO1 sequence
Check whether FIFO0 can be read or not
Check whether FIFO1 can be written to or not
Write 0-sized packet sequence to FIFO 0
Register Name
FIFO 0
FIFO 1
Actions
R/W
R/W
R/W
FIFO Register Address Table
USB Active Pipe Timing
00H 01H delay of 2 s, check 41H read* from FIFO0 register
and check if not ready (01H) 03H 02H
0AH 0BH delay of 2 s, check 4BH write* to FIFO1 register and
check if not ready (0BH) 09H 08H
00H 01H delay of 2 s, check 41H (if ready) or 01H
(if not ready) 00H
0AH 0BH delay of 2 s, check 4BH (if ready) or 0BH
(if not ready) 0AH
02H 03H delay of 2 s, check 43H 01H 00H
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terrupt and the Resume line (bit 3 of the USC) is set. In
order to make the HT82J97E/HT82J97A function prop-
erly, the programmer must set the USBCKEN (bit 3 of
the SCC) to 1 and clear the SUSP2 (bit4 of the SCC).
Since the Resume signal will be cleared before the Idle
signal is sent out by the host and the Suspend line (bit 0
of the USC) is going to 0 . So when the MCU is detect-
ing the Suspend line (bit0 of the USC), the Resume line
should be remembered and taken into consideration.
After finishing the resume signal, the suspend line will
go inactive and a USB interrupt is triggered. The follow-
ing is the timing diagram:
Register Address
MISC Setting Flow and Status
01001000B
01001001B
HT82J97E/HT82J97A
Data7~Data0
Data7~Data0
December 23, 2008
Bit7~Bit0