CLK
1
CLK
2
CLK
9
CLK
10
CLK
11
KCLK/
MCLK
t3 t4
t5
t2
t6
t1
KDAT/ Start Bit
Bit 0
Bit 7
Parity Bit Stop Bit
MDAT
FIGURE 33 – KEYBOARD/MOUSE RECEIVE/SEND DATA TIMING
NAME
DESCRIPTION
MIN
TYP
MAX
UNITS
t1
Time from DATA transition to falling edge of CLOCK
(Receive)
5
25
µsec
t2
Time from rising edge of CLOCK to DATA transition
(Receive)
5
T4-5
µsec
t3
t4
t5
Duration of CLOCK inactive (Receive/Send)
Duration of CLOCK active (Receive/Send)
Time to keyboard inhibit after clock 11 to ensure the
keyboard does not start another transmission (Receive)
Time from inactive to active CLOCK transition, used to
time when the auxiliary device samples DATA (Send)
30
30
>0
50
50
50
µsec
µsec
µsec
t6
5
25
µsec
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