Figure 43-26. DEC and Auto Character Mapping Order
SEGn
SEGn+1
SEGn+2
10
15
20
16
21
12
17
22
0
5
1
6
11
2
7
SEGn+3
13
18
23
3
8
SEGn+4
14
19
4
9
Auto Char Mapping
DEC=0
NSEG=4
SEGn+5
SEGn+6
SEGn+7
10
15
20
16
21
12
17
22
0
5
1
6
11
2
7
SEGn+8
13
18
23
3
8
SEGn+9
14
19
4
9
SEGn+10
SEGn+11
SEGn+12
10
15
20
16
21
12
17
22
0
5
1
6
11
2
7
SEGn+13
13
18
23
3
8
SEGn+14
14
19
4
9
Digit #0
Digit #1
Digit #2
STSEG
SEGn
SEGn+1
SEGn+2
SEGn+3
SEGn+4
Auto Char Mapping
DEC=1
NSEG=4
SEGn+5
SEGn+6
SEGn+7
SEGn+8
SEGn+9
SEGn+10
SEGn+11
SEGn+12
10
19
18
23
12
17
22
4
9
3
8
14
2
7
SEGn+13
11
16
21
1
6
SEGn+14
10
15
20
0
5
Digit #2
Digit #1
Digit #0
STSEG
10
19
18
23
12
17
22
4
9
3
8
14
2
7
11
16
21
1
6
10
15
20
0
5
10
19
18
23
12
17
22
4
9
3
8
14
2
7
11
16
21
1
6
10
15
20
0
5
COM0
COM1
COM2
COM3
COM4
COM5
COM6
COM7
COM0
COM1
COM2
COM3
COM4
COM5
COM6
COM7
There are two usage models available under ACM, defined by the Mode bit in the Automated Character
Mapping Configuration register (ACMCFG.MODE): when MODE=0, the
Sequential Characters String
Display
mode is selected. When MODE=1, the
Scrolling of Characters String Display
mode is selected.
Both modes use the character mapping configuration (see
mapped with contiguous SEG/COM lines in order to increment the index for the next digit automatically.
For example when the first digit is mapped on SEG2 and SEG3 lines, the second digit must be mapped
on SEG4 and SEG5 lines.
Sequential Characters String Display
This mode displays characters of a string on a digits chain on the LCD panel. The characters string is split
in several sub strings, which are to be displayed sequentially at a selected frequency (frame counter
basis). It requires an internal frame counter (time base) and the DMA controller to transfer the sub strings.
To use this mode, character mapping must be configured first (see
configuration must be done to specify the sequential display. In the Automated Character Mapping
Configuration register (ACMCFG):
•
Write the size of the digits chain on LCD panel to the Number of Digit bits (ACMCFG.NDIG).
•
Write a '0' to the Mode bit in order to select the sequential mode (ACMCFG.MODE).
•
Configure a frame counter to set the display period (period between two sub strings display, see
), and write the frame counter index to the Frame Counter Selection bits
(ACMCFG.FCS).
The DMA controller should be configured to transfer several blocks corresponding to the sub strings.
Each block size is equal to the number of digit on the LCD panel (sub strings may require some blank
characters in order to be displayed correctly). The number of blocks is the number of sub strings required
to display the complete characters string. To repeat the complete character string display, the DMA
controller should repeat the total blocks transfer. The DMA must write the blocks to the Character
Mapping Segments Data register (CMDATA).
To enable the sequential characters string display, write a '1' to the Automated Character Mapping Enable
bit in the Control B register (CTRLB.ACMEN); write a '0' to CTRLB.ACMEN to disable it.
Atmel SAM L22G / L22J / L22N [DATASHEET]
Atmel-42402E-SAM L22G / L22J / L22N_Datasheet_Complete-07/2016
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