HD66712 Datasheet, PDF (35/88 Pages) Hitachi Semiconductor – Dot-Matrix Liquid Crystal Display Controller/Driver

HD66712U
Reset Function
Initializing by Internal Reset Circuit
An internal reset circuit automatically initializes the HD66712 when the power is turned on. The
following instructions are executed during the initialization. The busy flag (BF) is kept in the busy state
until the initialization ends (BF = 1). The busy state lasts for 15 ms after V_CC rises to 4.5V or 40 ms after
the V_CC rises to 2.7V.
1. Display clear:
(20)H to all DDRAM
2. Set functions:
DL = 1: 8-bit interface data
N = 1: 2-line display
RE = 0: Extension register write disable
BE = 0: CGRAM/SEGRAM blink off
LP = 0: Not in low power mode
3. Control display on/off:
D = 0: Display off
C = 0: Cursor off
B = 0: Blinking off
4. Set entry mode:
I/D = 1: Increment by 1
S = 0: No shift
5. Set extension function:
FW = 0: 5-dot character width
B/W = 0: Normal cursor (eighth line)
NW = 0: 1- or 2-line display (depending on N)
6. Enable scroll:
HSE = 0000: Scroll unable
7. Set scroll amount:
HDS = 000000: Not scroll
Note: If the electrical characteristics conditions listed under the Table Power Supply Conditions Using
Internal Reset Circuit are not met, the internal reset circuit will not operate normally and will fail
to initialize the HD66712.
Initializing by Hardware Reset Input
The HD66712 also has a reset input pin: RESET*. If this pin is made low during operation, an internal
reset and initialization is performed. This pin is ignored, however, during the internal reset period at
power-on.
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