IBM uPD78082 - Manual (Page 141)

118
CHAPTER 9 BUZZER OUTPUT CONTROL CIRCUIT
PM37
7
PM36
6
PM35 PM34
4
PM33
3 2 1 0
FF23H
Address
PM3
Symbol
PM32 PM31 PM30
5
FFH
After
Reset
R/W
R/W
PM3n
0
1
P3n Pin Input/Output Mode Selection (n=0 to 7)
Output mode (output buffer ON)
Input mode (output buffer OFF)
(2) Port mode register 3 (PM3)
This register sets port 3 input/output in 1-bit units.
When using the P36/BUZ pin for buzzer output function, set PM36 and output latch of P36 to 0.
PM3 is set with a 1-bit or 8-bit memory manipulation instruction.
RESET input sets PM3 to FFH.
Figure 9-3. Port Mode Register 3 Format