Rainbow Electronics AT77C104B - Manual (Page 19)

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AT77C104B
5347B–BIOM–08/04
Note: In the PS/2 protocol, bits b2 and b1 are used to code the middle and right buttons
respectively, and b3 is set to high.
Absolute X Movement Register (0 to 255 Pixels )
Absolute Y Movement Register (0 to 255 Pixels)
Note: When a click is detected, the information is placed in the b7 bit of the status register and
in the b1 bit of the general navigation register. The reading of the status register initial-
izes the b7 bit but does not initialize the b1 bit of the general navigation register. The host
must carefully correlate the two bits.
b7 b6 b5 b4 b3 b2 b1 b0
XMOV (MSB) – – – – – – XMOV (LSB)
0 0 0 0 0 0 0 0
b7 b6 b5 b4 b3 b2 b1 b0
YMOV (MSB) – – – – – – YMOV (LSB)
0 0 0 0 0 0 0 0