w83977ctf Winbond Electronics Corp America, w83977ctf Datasheet - Page 130

• Manufacturer Part Number: w83977ctf
• Description: Winbond I/o
• Manufacturer: Winbond Electronics Corp America

CRF1 (Default 0x00)
Bit 2: FDCPME. FDC auto power management enable.
Bit 1: URAPME. UART A auto power management enable.
Bit 0: URBPME. UART B auto power management enable.
Bit 5 - 4: Reserved. Return zero when read.
Bit 3 - 0: Devices' trap status.
Bit 3: PRTTRAPSTS. Printer port trap status.
Bit 7: WAK_STS. This bit is set when the chip is in the sleeping state and an enabled resume
Bit 6: Device's trap status.
Bit 6: URCTRAPSTS. UART C trap status.
These bits of trap status indicate that the individual device Wakes-Up due to any I/O access,
event occurs. Upon setting this bit, the sleeping/working state machine will transition the
system to the working state. This bit is only set by hardware, and is cleared by writing a 1 to
this bit position, or by the sleeping/working state machine automatically when the global
standby timer expires.
= 0
= 1
IRQ, and external input to the device. The device's idle timer reloads the preset expiry
depending on which device wakes up. These 5 bits are controlled by the UART C, printer
= 0
= 1
= 0
= 1
= 0
= 1
port, FDC, UART A and UART B power down machines respectively . Writing a 1 clears this
bit and writing a 0 has no effect. Note that: the user is not supposed to change the status
while power management function is enabled.
= 0
= 1
= 0
= 1
disable the auto power management functions.
enable the auto power management functions.
disable the auto power management functions.
enable the auto power management functions.
disable the auto power management functions.
enable the auto power management functions.
the chip is in the sleeping state.
the chip is in the working state.
UART C is now in the sleeping state.
UART C is now in the working state due to any UART C access, any IRQ, the
receiver begins receiving a start bit, the transmitter shift register begins transmitting a
start bit, or any transition on MODEM control input lines.
the printer port is now in the sleeping state.
the printer port is now in the workinging state due to any printer port access, any IRQ,
any DMA acknowledge, or any transition on BUSY, ACK#, PE, SLCT, and ERR#
pins.
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Publication Release Date: March 1999
W83977EF/ CTF
PRELIMINARY
Revision A1