HD6433802H Datasheet, PDF (177/435 Pages) Hitachi Semiconductor – Single-Chip Microcomputer

2. Port mode register 9 (PMR9)
Bit
7
6
5
4
3
2
1
0
—
—
—
—
PIOFF
—
PWM₂ PWM₁
Initial value
1
1
1
1
0
—
0
0
Read/Write
—
—
—
—
R/W
W
R/W R/W
PMR9 is an 8-bit read/write register controlling the selection of the P9₀ and P9₁ pin functions.
Bit 3: P9₂ to P9₀ step-up circuit control (PIOFF)
Bit 3 turns the P9₂ to P9₀ step-up circuit on and off.
Bit 3
PIOFF
Description
0
Large-current port step-up circuit is turned on
(initial value)
1
Large-current port step-up circuit is turned off
Note:
When turning the step-up circuit on or off, the register must be rewritten only when the
buffer NMOS is off (port data is 1).
When turning the step-up circuit on, first clear PIOFF to 0, then wait for the elapse of 30
system clock before turning the buffer NMOS on (clearing port data to 0).
Without the elapse of the 30 system clock interval the step-up circuit will not start up, and it
will not be possible for a large current to flow, making operation unstable.
Port 9 Pin Output Low Level Permitted Currents
Pin
Symbol Test Conditions Min
Typ
P9₂ to P9₀ I_OL
V_CC = 1.8 V to 5.5 V* —
—
P9₃ to P9₅
—
—
Note: * For details, see section 14.2.2, DC Characteristics.
Max
25 mA*
10 mA
10 mA
PIOFF Bit Value
0
1
—
Bit 2: Reserved bit
Bit 2 is reserved; only 0 can be written to this bit.
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