PEDL9090-02
¡ Semiconductor
ML9090-01,-02
• Port register A (PTA)
D7
D6
D5
D4
—
D3
D2
D1
D0
PTA
The port register A sets (to “1”) and resets (to “0”) general-purpose port A data. The setting of
the PTA bit (D0 bit) corresponds to the PA0 output pin. If the RESET pin is pulled to a “L” level,
this register is reset to “0” and the PA0 pin goes to high impedance. After the RESET pin is pulled
to a “H” level, if port data is set in this register, the PA0 pin is released from its high impedance
state and outputs the corresponding port data.
• Port register B (PTB)
D7
D6
D5
D4
D3
D2
D1
D0
PTB7
PTB6
PTB5
PTB4
PTB3
PTB2
PTB1
PTB0
The port register sets (to “1”) and resets (to “0”) general-purpose port B data. The settings of the
PTB0 to PTB7 bits (D0 to D7 bits) correspond to the PTB0 to PTB7 output pins. If the RESET pin
is pulled to a “L” level, this register is reset to “0” and pins PTB0 through PTB7 go to high
impedance. After the RESET pin is pulled to a “H” level, if port data is set in this register, pins
PTB0 through PTB7 are released from their high impedance states and output the corresponding
port data.
• Control register 1 (FCR1)
D7
D6
D5
KT
D4
D3
—
D2
—
D1
D0
INC
WLS
SHL
DTY1
DTY0
(1) D7 INC Address increment direction
1: X direction address increment
0: Y direction address increment
This bit sets the address increment direction of the display RAM. The display RAM address is
automatically incremented by 1 every time data is written to the display data register. Writing
a “1” to this bit sets “X address increment”, and writing a “0” sets “Y address increment”. For
further details regarding address incrementing, refer to the page entitled “X, Y Address Counter
Auto Increment”, Even if the RESET pin is pulled to a “L” level, the value of this bit will not
change.
(2) D6 WLS (Word Length Select)
1: 6-bit word length select
0: 8-bit word length select
This bit selects the word length of data to be written to and read from the display RAM. If “1”
is written to this bit, data will be read from and written to the display RAM in 6-bit units. If “0”
is written to this bit, data will be read from and written to the display RAM in 8-bit units. Even
if the RESET pin is pulled to a “L” level, the value of this bit will not change.
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