Rainbow Electronics MAX6963 - Manual (Page 14)

MAX6960–MAX6963
4-Wire Serially Interfaced
8 x 8 Matrix Graphic LED Drivers
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observing the setup and hold times. Bit D15 is low,
indicating a write command.
For a 24-bit transmission:
Clock 24 bits of data into DIN, D23 first to D0 last,
observing the setup and hold times. Bit D23 is low,
indicating a write command.
4) Take CS high (while CLK is still high after clocking
in the last data bit).
5) Take CLK low.
Reading Device Registers
Any register data within the MAX6960 may be read by
sending a logic-high to bit D15. The sequence is:
1) Take CLK low.
2) Take CS low.
3) For a 16-bit transmission:
Clock 16 bits of data into DIN, D15 first to D0 last,
observing the setup and hold times. Bit D15 is high,
indicating a read command. Bits D7 to D0 are
dummy bits, and are discarded by the MAX6960.
For a 24-bit transmission: Clock 24 bits of data into
DIN, D23 first to D0 last, observing the setup and
hold times. Bit D23 is high, indicating a read com-
mand. Bits D7 to D0 are dummy bits, and are dis-
carded by the MAX6960.
4) Take CS high (while CLK is still high after clocking
in the last data bit).
5) Take CLK low.
6) The selected MAX6960’s DOUT is enabled from tri-
state for read back.
7) Clock 8 bits of data from DOUT, D7 first to D0 last,
observing the setup and hold times.
8) Take CLK low after the final (8th) data bit.
The selected MAX6960’s DOUT returns to tri-state.
Figure 10 shows a read operation when 24 bits are
transmitted and 8 bits are read back.
Local 3-Wire Serial Interface
The MAX6960 uses a 3-wire interface to bus together
up to 256 MAX6960s. The 3-wire bus enables each
device to calculate its own unique driver address
(0 to 255), and reconfigure its display memory. The
ADDOUT output also provides an interrupt at every
page change, when the plane counter is configured to
automatic (Table 30).
D7 D6 D5 D4 D3 D2 D1
CS
CLK
DIN
DOUT
D15
= 1
TRI-STATE
D14 D13 D12 D11 D10 D9 D8 D0
.
D7 D6 D5 D4 D3 D2 D1 D0
Figure 9. 16-Bit Read from the MAX6960–MAX6963
D22 D21 D20 D19 D18 D7 D6 D5 D4 D3 D2 D1
CS
CLK
DIN
DOUT
D23
= 1
TRI-STATE
D14 D13 D12 D11 D10 D9 D8 D16 D15 D17 D0
.
D7 D6 D5 D4 D3 D2 D1 D0
Figure 10. 24-Bit Read from the MAX6960–MAX6963