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BD VFDs Application Note APN140

4. CONTROL PROCEDURE

4.3 Full Dotmatrix Type (For MNxxxxx series)

Some of full dotmatrix type (p/n MN series) requests a particular procedure of grid scan and data protocol.
There are four types of data protocols in the MNxxxxx series BDVFDs.

Table 3 List of MN Series
TypeDriverAnode
Separation		 Availabilities
(as of July 1998)
1.Grid/Anode
Hybrid		4N/A
2.8MN12808B, MN12818A/AB
3.Grid/Anode
Independent		4 MN12832E/EC, MN12864H, MN16016F, MN25664D
4.8MN19216G, MN25616P

4.3.1 Grid Anode Hybrid Type

The Grid/Anode Hybrid type of MN series basically has the same data protocol as in the section 4.2.1. See carefully the individual specification for details.

4.3.2 Grid Anode Independent Type

The Grid/Anode Independent type 3 and 4 has two anode data inputs. This is because the anode are controlled by separated two anode drivers.
In type 3, Anode Driver 1 controls A and D anodes, and Anode Driver 2 controls B and C anodes. In type 4, Anode Driver 1 controls a, b, g and h anodes, Anode Driver 2 controls d, e, f and g anodes separately.

Table 4 Anode Drivers of MN Series G/A Independet type
TypeAnode
Separation		Anode Driver 1
controls;		 Anode Driver 2
controls;		Grid Anode
Assignment
3.4

A/B/C/D		A and D anodeB and C anode
4.8

a/b/c/d
e/f/g/h		a, b, g and h anodec, d, e and f anode

4.3.2.1 Control Procedure of Grid Anode Independent Type

The following table and timing chart are example of grid scan and anode data controls.

Table 5 Example of Grid Scan and Anode Data Protocol (MN12832E)
TimingGrid
to be
selected		Grid Driver Output Blanking
control		Anode data
to be
turned on
G1G2G3G4G5-- G60G61G62G63G64BK1BK2SI1/SI2
T64G63+G64LLLLLL LLLHHHLB and C
T1G64+G1HLLLLL LLLLHLHA and D
T2G1+G2HHLLLL LLLLLHLB and C
T3G2+G3LHHLLL LLLLLLHA and D
T4G3+G4LLHHLL LLLLLHLB and C
T5G4+G5LLLHHL LLLLLLHA and D
::::::::: :::::::
T61G60+G61LLLLLL HHLLLLHA and D
T62G61+G62LLLLLL LHHLLHLB and C
T63G62+G63LLLLLL LLHHLLHA and D
T64G63+G64LLLLL LLLLHHHLB and C
T1G64+G1HLLLL LLLLLHLHA and D



Fig.17d Timing Chart for MN12832E

(1) Grid Scan

In case of Grid Anode Independent type, the grid scan is made semiautomatically by setting LATG=H and sending one CLKG pulse a timing as in Figure 17d.
In the inter-digit blanking time (*), send one clock to CLKG. The SIG is needed to be set H in just inter-digit blanking between T64-T1 and T1-T2. In the other timing, SIG should be set L.

(2) Anode Data

Serial data input SI1 and SI2 to be connected as in figure 17e.
For example, in timing T2, Grid G1 and G2 are selected and turned on by semiautomatic grid scan. In this timing T2, set Anode Driver 2 ACTIVE by setting BK2=L, and set Anode Driver 1 INACTIVE by setting BK1=H, as shown in the above Table 5 or 6.
In timing T2, only anode group B and C in the grid G1 and G2 area can be selectively turned on. All of anode A and D group are turned off automatically by setting BK1=H, in this timing T2.
Practically, the B and C anode data for timing T2 to be sent in period of timing T1 into the shift-register of Anode Driver 2. Then, Driver 1 have data for Driver 2, but it does not make sense because Anode Driver 1 is INACTIVE in timing T2.
In the next timing T3, set Anode Driver 1 ACTIVE by setting BK1=L, and set Anode Driver 2 INACTIVE by setting BK2=H. In timing T3, the Anode Driver1 outputs the A and D anode data for grid G2 and G3.

Following table shows an example of data needed to send to display a character of "A".

Table 6 Data Example
Timing BK1BK2 Anode Data (SI1/SI2)
Refer to Shift Register Assignment shown
in the individual specification.
DO1DO2DO3DO4 DO5DO6DO7DO8 DO9DO10DO11DO12 DO13DO14..
T1LH LLLLHLHL HLHLHL..
T2HL H LLHLLLL HHLLLL..
T3LH LLLHH LHLHHHL HL..
T4HL LLLLLLLLL LLLLL..
::: ::::::::: ::::::

(3) Drive Circuit

Figure 17e shows an example of driving circuit for MN12832E.

Fig.17e Block Diagram and Drive Circuit for MN12832E
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