em78p257 ELAN Microelectronics Corp, em78p257 Datasheet - Page 58

• Manufacturer Part Number: em78p257
• Description: 8-bit Microcontroller
• Manufacturer: ELAN Microelectronics Corp

This specification is subject to change without prior notice.
Table 26 MOUSE AC electrical characteristics (T
Key Debounce
Rising Edge Crossed Width Fosc=35 KHz
Falling Edge Crossed Width Fosc=35 KHz
Mouse CLK Active Time
Mouse CLK Inactive Time
Mouse Sample DATA from CLK rising Edge
System CLK Active Time
System CLK Inactive Time
Time from DATA Transition to Falling Edge of CLK
Time from rising Edge of CLK to DATA Transition
Time to mouse Inhibit after the 11
does not start another Transmission
In Oscillating Frequency = 34.3 KHz.
18
16
14
12
10
DATA to low, and clock once more. If framing error occurs, EM78P257A/B continues to clock until
DATA is high, then clocks the line control bit and requests for a Resend. When the system sends
out a command or data transmission that requires a response, the system waits for EM78P257A/B
to respond before sending its next output.
8
6
4
2
0
Parameters
X1,X2,Y1,Y2,Z1,Z2 INPUT IMPEDANCE
th
CLK to ensure mouse
VOLTS(LIN)
A
= 0¢J to 70¢J)
58
Tmca
Tmdc
Sym.
Tmci
Tsca
Tsdc
Tscd
Tsci
Tkd
Tpi
Tr
Tf
Min.
14.3
14.3
0
-
-
-
-
-
-
-
-
Typ.
42.9
42.9
14.3
42.9
42.9
14.3
28.6
12
-
-
-
EM78P257
Max.
50
07.27.2004 (V1.4)
OTP ROM
-
-
-
-
-
-
-
-
-
-
MAX
TYP
MIN
Unit
ms
us
us
us
us
us
us
us
us
us
us