KB3910 Ver la hoja de datos (PDF) - Unspecified
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KB3910 Datasheet PDF : 80 Pages
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KB3920 Keyboard Controller Datasheet
3.2.9 Digital to Analog Pin Descriptions
Pin Name Pin No Direction Description
DA[3:0] 80,79,
O
78,76
Digital to Analog Conversion Output with 8-bit resolution.
3.2.10 8051 External Interface Pin Descriptions
Pin Name Pin Direction Description
No
E51CS# 99
O
E51TXD 34
O
E51RXD 35
I
E51CLK 35
I
E51TMR0 101
I
E51INT0 102
I
This pin is used for debug purpose only.
The E51CS# is used to select auxiliary memory region on a development
board. The auxiliary memory is usually a SRAM device used to store 8051’s
firmware code to facilitate real-time debugging such as setting break points.
Register XBICS enables the mapping of the four 16K segments (SEG3-0)
memory spaces individually into auxiliary memories. When a particular
segment is enabled, E51CS# will be asserted instead of SELMEM# for
memory accesses such that auxiliary memory device (SRAM) will be
accessed instead of the flash BIOS memory. The assertion of E51CS# and
SELMEM# is mutually exclusive.
These two pins are for debug purpose only.
E51TXD/ E51RXD are the Transmit/Receive signals of the 8051’s serial port.
They can be connected to an external RS232 transceiver and communicate
with another PC’s COM port by sending debug code
If 8051 serial port selects MODE 0 (shift register), E51RXD becomes
ETh5e1CInLpKu.t pulse to the clock input of the 8051’s timer_0
The interrupt signal to the embedded 8051
3.2.11 Clock Pin Descriptions
Pin name
Pin
No
Direction
Description
XCLKI 138
I
XCLKO 140
O
32.768KHz Input.
32.768KHz Output
3.2.12 Miscellaneous Pin Descriptions
Pin name Pin Direction
No
SCI# 24
O
GA20 1
O
KBRST# 2
O
ECRST# 42
I
Description
The SCI# signal is output to system chipset to indicate an outstanding SCI
The GA20 signal is output to system chipset.
The KBRST# is output to system chipset to generate a system reset.
ECRST# is used as the Global Reset signal for the whole chip.
Copyright©2006, ENE Technology Inc.
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