Section 22 USB Function Module (USB)
Rev. 1.00 Mar. 12, 2008 Page 838 of 1178
REJ09B0403-0100
22.3.2
Interrupt Flag Register 1 (IFR1)
IFR1, together with interrupt flag registers 0 and 2 (IFR0 and IFR2), indicates interrupt status
information required by the application. When an interrupt source is generated, the corresponding
bit is set to 1. And then this bit, in combination with interrupt enable register 1 (IER1), generates
an interrupt request to the CPU. To clear, write 0 to the bit to be cleared and 1 to the other bits.
Bit Bit
Name
Initial
Value
R/W Description
7 to 4
All
0
R
Reserved
These bits are always read as 0. The initial value
should not be changed.
3 VBUS
MN
0 R
This is a status bit which monitors the state of the
VBUS pin.
This bit reflects the state of the VBUS pin and
generates no interrupt request. This bit is always 0
when the PULLUP_E bit in DMA is 0.
2
EP3 TR
0
R/W
EP3 Transfer Request
This bit is set if there is no valid transmit data in the
FIFO buffer when an IN token for endpoint 3 is
received from the host. A NAK handshake is returned
to the host until data is written to the FIFO buffer and
packet transmission is enabled.
1
EP3 TS
0
R/W
EP3 Transmit Complete
This bit is set when data is transmitted to the host from
endpoint 3 and an ACK handshake is returned.
0
VBUSF
0
R/W
USB Disconnection Detection
When the function is connected to the USB bus or
disconnected from it, this bit is set to 1. The VBUS pin
of this module is used for detecting connection or
disconnection.
Summary of Contents for H8S Family
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Page 70: ...Section 1 Overview Rev 1 00 Mar 12 2008 Page 22 of 1178 REJ09B0403 0100...
Page 108: ...Section 2 CPU Rev 1 00 Mar 12 2008 Page 60 of 1178 REJ09B0403 0100...
Page 116: ...Section 3 MCU Operating Modes Rev 1 00 Mar 12 2008 Page 68 of 1178 REJ09B0403 0100...
Page 152: ...Section 5 Interrupt Controller Rev 1 00 Mar 12 2008 Page 104 of 1178 REJ09B0403 0100...
Page 206: ...Section 6 Bus Controller BSC Rev 1 00 Mar 12 2008 Page 158 of 1178 REJ09B0403 0100...
Page 420: ...Section 9 14 Bit PWM Timer PWMX Rev 1 00 Mar 12 2008 Page 372 of 1178 REJ09B0403 0100...
Page 476: ...Section 12 Watchdog Timer WDT Rev 1 00 Mar 12 2008 Page 428 of 1178 REJ09B0403 0100...
Page 552: ...Section 14 CRC Operation Circuit CRC Rev 1 00 Mar 12 2008 Page 504 of 1178 REJ09B0403 0100...
Page 712: ...Section 18 I2 C Bus Interface IIC Rev 1 00 Mar 12 2008 Page 664 of 1178 REJ09B0403 0100...
Page 804: ...Section 19 LPC Interface LPC Rev 1 00 Mar 12 2008 Page 756 of 1178 REJ09B0403 0100...
Page 838: ...Section 20 Ethernet Controller EtherC Rev 1 00 Mar 12 2008 Page 790 of 1178 REJ09B0403 0100...
Page 964: ...Section 24 RAM Rev 1 00 Mar 12 2008 Page 916 of 1178 REJ09B0403 0100...
Page 1066: ...Section 25 Flash Memory Rev 1 00 Mar 12 2008 Page 1018 of 1178 REJ09B0403 0100...
Page 1098: ...Section 26 Boundary Scan JTAG Rev 1 00 Mar 12 2008 Page 1050 of 1178 REJ09B0403 0100...
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