W83977G Winbond Electronics Corp America, W83977G Datasheet - Page 123

• Manufacturer Part Number: W83977G
• Description: W83877TF plus KBC, CIR, RTC, Pb-free
• Manufacturer: Winbond Electronics Corp America

11.2 Alternate I/O Functions
W83977F/G, W83977AF/AG provides several alternate functions which are scattered among the GP
I/O ports. Table 11.2.1 shows their assignments. Polarity bit can also be set to alter their polarity of
alternate functions.
Table 11.2.1
11.2.1
GP10 and GP11 can be programmed to map their own interrupt channels. The selection of IRQ
channel can be done in configure registers CR70 and CR72 of logical device 7. Each interrupt
channel also has its own 1 ms debounce filter that is used to reject any noise which is equal to or less
than 1 ms wide.
11.2.2
Watch Dog Timer contains a one minutes resolution down counter, CRF2 of Logical Device 8, and two
watch Dog control registers, WDT_CTRL0 and WDT_CTRL1 of Logical Device 8. The down counter
can be programmed within the range from 1 to 255 minutes. Writing any new non-zero value to CRF2
or reset signal coming from a Mouse interrupt or Keyboard interrupt (CRF2 also contains non-zero
value) will cause the Watch Dog Timer to reload and start to count down from the new value. As the
counter reaches zero, (1) Watch Dog Timer time-out occurs and the bit 0 of WDT_CTRL1 will be set
to logic 1; (2) Watch Dog interrupt output is asserted if the interrupt is enable in CR72 of logical device
8; and (3) Power LED starts to toggle output if the bit 3 of WDT_CTRL0 is enabled. WDT_CTRL1
also can be accessed through GP2 I/O base address + 1.
W83977F-A/ W83977G-A/ W83977AF-A/ W83977AG-A
GP I/O PORT
GP10
GP11
GP12
GP13
GP14
GP15
GP16
GP17
GP20
GP21
GP22
GP23
GP24
GP25
Interrupt Steering
Watch Dog Timer Output
Interrupt Steering
Interrupt Steering
Watching Dog Timer Output/IRRX input
Power LED output/ IRTX output [W83977AF only]
General Purpose Address Decoder/ Keyboard Inhibit(P17)
General Purpose Write Strobe/ 8042 P12
Watching Dog Timer Output
Power LED output
Keyboard Reset (8042 P20)
8042 P13
8042 P14
8042 P15
8042 P16
GATE A20 (8042 P21)
-115 -
ALTERNATE FUNCTION
Publication Release Date: May 2006
Revision 0.60