Datasheet

Scan-Limit Register
The scan-limit register sets how many digits are displayed,
from 1 to 8. They are displayed in a multiplexed manner
with a typical display scan rate of 800Hz with 8 digits
displayed. If fewer digits are displayed, the scan rate is
8f
OSC
/N, where N is the number of digits scanned. Since
the number of scanned digits affects the display bright-
ness, the scan-limit register should not be used to blank
portions of the display (such as leading zero suppression).
Table 8 lists the scan-limit register format.
Table 8. Scan-Limit Register Format (Address (Hex) = 0xXB)
Table 7. Intensity Register Format (Address (Hex) = 0xXA)
*See Scan-Limit Register section for application.
DUTY CYCLE
D7 D6 D5 D4 D3 D2 D1 D0
HEX
CODE
MAX7219 MAX7221
1/32
(min on)
1/16
(min on)
X X X X 0 0 0 0 0xX0
3/32 2/16 X X X X 0 0 0 1 0xX1
5/32 3/16 X X X X 0 0 1 0 0xX2
7/32 4/16 X X X X 0 0 1 1 0xX3
9/32 5/16 X X X X 0 1 0 0 0xX4
11/32 6/16 X X X X 0 1 0 1 0xX5
13/32 7/16 X X X X 0 1 1 0 0xX6
15/32 8/16 X X X X 0 1 1 1 0xX7
17/32 9/16 X X X X 1 0 0 0 0xX8
19/32 10/16 X X X X 1 0 0 1 0xX9
21/32 11/16 X X X X 1 0 1 0 0xXA
23/32 12/16 X X X X 1 0 1 1 0xXB
25/32 13/16 X X X X 1 1 0 0 0xXC
27/32 14/16 X X X X 1 1 0 1 0xXD
29/32 15/16 X X X X 1 1 1 0 0xXE
31/32
15/16
(max on)
X X X X 1 1 1 1 0xXF
SCAN LIMIT
REGISTER DATA
HEX
CODE
D7 D6 D5 D4 D3 D2 D1 D0
Display digit 0 only* X X X X X 0 0 0 0xX0
Display digits 0 & 1* X X X X X 0 0 1 0xX1
Display digits 0 1 2* X X X X X 0 1 0 0xX2
Display digits 0 1 2 3 X X X X X 0 1 1 0xX3
Display digits 0 1 2 3 4 X X X X X 1 0 0 0xX4
Display digits 0 1 2 3 4 5 X X X X X 1 0 1 0xX5
Display digits 0 1 2 3 4 5 6 X X X X X 1 1 0 0xX6
Display digits 0 1 2 3 4 5 6 7 X X X X X 1 1 1 0xX7
MAX7219/MAX7221 Serially Interfaced, 8-Digit LED Display Drivers
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