at89c5131 ATMEL Corporation, at89c5131 Datasheet - Page 133

• Manufacturer Part Number: at89c5131
• Description: 8-bit Flash Microcontroller With Full Speed Usb Device At89c5131
• Manufacturer: ATMEL Corporation

Detach Simulation
Figure 66. Disconnect Timing
USB Interrupt System
Interrupt System Priorities
4136C–USB–04/05
D+
D-
V
IHZ
(min)
V
V
IL
SS
Controller
USB
D+
D-
Disconnected
In order to be re-enumerated by the Host, the AT89C5131 has the possibility to simulate
a DETACH - ATTACH of the USB bus.
The V
D+ pull-up as shown in Figure 65. This output can be put in high-impedance when the
DETACH bit is set to 1 in the USBCON register. Maintaining this output in high imped-
ance for more than 3 µs will simulate the disconnection of the device. When resetting
the DETACH bit, an attach is then simulated.
Figure 65. Example of V
Figure 67. USB Interrupt Control System
Device
REF
output voltage is between 3.0V and 3.6V. This output can be connected to the
EUSB
IE1.6
Interrupt Enable
AT89C5131
> = 2,5 µs
REF
IE0.7
EA
Connection
V
REF
D-
D+
Disconnect
Detected
Priority Enable
IPH/L
1.5 kΩ
00
01
10
11
Lowest Priority Interrupts
1
2
3
4
USB-B Connector
V
D-
D+
GND
CC
AT89C5131
131