PT6314_10 Datasheet, PDF (19/42 Pages) Princeton Technology Corp – Dot Character VFD Controller/Driver IC

PT6314
5.5 TIMING GENERATION CIRCUIT
Timing signals for internal circuit operations(i.e. DDRAM, CGRAM) are generated by the Timing Generation Circuit. The
Display RAM Read timing and the MCU access internal operation timing are generated separately in order to avoid
interferences. Thus, for example, when data is being written to the DDRAM, no undesirable interference occur (i.e.
flickering in areas other than the display location)
5.6 VFD DRIVER CIRCUIT
The VFD Driver Circuit is composed of 24 grid and 80 segment signal drivers. During power On, the character font and
number of digits are selected by the hardware (DS0 and DS1), the required grid signal drivers automatically output drive
waveforms while the other grid signal drivers continue to output non-selected waveforms. The serial data sent is latched
when the display data character pattern corresponding to the last address of the display data RAM (DDRAM). Since the
serial data is latched when the display data character pattern corresponding to the starting address enters the internal
shift register, PT6314 drives from the head display.
5.7 CURSOR/BLINK CONTROL CIRCUIT
Cursor and Character blinking are generated by the Cursor / Blink Control Circuit. The cursor or the blinking will appear
with the digit located at the display data RAM (DDRAM) address set in the address counter (AC).
For example, when the address counter is 08H, the cursor position is displayed at DDRAM Address 08H.
AC6 AC5 AC4 AC3 AC2 AC1 AC0
AC
0
0
0
1
0
0
0
5.7.1 FOR 1-LINE DISPLAY:
Display position
Digit
1 2 3 4 5 6 7 8 9 10 11 12
DDRAM Address(hexadecimal) 00 01 02 03 04 05 06 07 08 09 0A 0B
Cursor Position
5.7.2 FOR 2-LINE DISPLAY:
Display position
Digit
1 2 3 4 5 6 7 8 9 10 11 12
DDRAM Address(hexadecimal)
00 01 02 03 04 05 06 07 08 09 0A 0B
40 41 42 43 44 45 46 47 48 49 4A 4B
Cursor Position
Note:
The cursor or blinking appears when the address counter (AC) selects the Character Generator RAM (CGRAM). The cursor and blinking become
meaningless. When the Address Counter is a CGRAM Address, the cursor or the blinking is displayed in a meaningless position.
V1.5
19
October 2009