MAX7313 Maxim, MAX7313 Datasheet - Page 16

• Manufacturer Part Number: MAX7313
• Description: The MAX7313 I²C-compatible serial interfaced peripheral provides microprocessors with 16 I/O ports
• Manufacturer: Maxim

If blinking is enabled, then both interrupt output con-
trols O0 and O1 set the logic state of the INT/O16 pin
according to the blink phase. PWM intensity control for
O16 is set by the 4 global intensity bits in the master
and O16 intensity register (Table 13).
In blink mode, the output ports can be flipped between
using either the blink phase 0 registers or the blink phase
1 registers. Flip control is by software control (the blink
flip flag B in the configuration register) (Table 4). If hard-
ware flip control is needed, consider the MAX7314, which
includes a BLINK input, as well as software control.
The blink function can be used for LED effects by pro-
gramming different display patterns in the two sets of
output port registers, and using the software or hard-
ware controls to flip between the patterns.
If the blink phase 1 registers are written with 0xFF, then
the BLINK input can be used as a hardware disable to,
for example, instantly turn off an LED pattern pro-
grammed into the blink phase 0 registers. This tech-
nique can be further extended by driving the BLINK
input with a PWM signal to modulate the LED current to
provide fading effects.
The blink mode is enabled by setting the blink enable
flag E in the configuration register (Table 4). When blink
mode is enabled, the state of the blink flip flag sets the
phase, and the output ports are set by either the blink
phase 0 registers or the blink phase 1 registers (Table 7).
16-Port I/O Expander with LED Intensity
Control, Interrupt, and Hot-Insertion Protection
Table 5. Ports Configuration Registers
Table 6. Input Ports Registers
16
Read back ports configuration P15–P8
Read back ports configuration P7–P0
______________________________________________________________________________________
Ports configuration P15–P8
Ports configuration P7–P0
Read input ports P15–P8
Read input ports P7–P0
(1 = input, 0 = output)
(1 = input, 0 = output)
REGISTER
REGISTER
R/W
R/W
0
1
0
1
1
1
Blink Mode
ADDRESS
ADDRESS
CODE
CODE
(HEX)
(HEX)
0x06
0x07
0x00
0x01
OP15
OP7
IP15
IP7
D7
D7
The blink mode is disabled by clearing the blink enable
flag E in the configuration register (Table 4). When blink
mode is disabled, the state of the blink flip flag is
ignored, and the blink phase 0 registers alone control
the output ports.
When the blink function is disabled, the two blink phase
0 registers set the logic levels of the 16 ports (P0 through
P15) when configured as outputs (Table 8). A duplicate
pair of registers called the blink phase 1 registers are
also used if the blink function is enabled (Table 9). A
logic high sets the appropriate output port high imped-
ance, while a logic low makes the port go low.
Reading a blink phase register reads the value stored
in the register, not the actual port condition. The port
output itself may or may not be at a valid logic level,
depending on the external load connected.
Table 7. Blink Controls
X = Don’t care.
ENABLE
FLAG E
BLINK
OP14
IP14
OP6
IP6
D6
D6
0
1
OP13
OP5
IP13
IP5
D5
D5
FLAG B
REGISTER DATA
REGISTER DATA
BLINK
FLIP
OP12
OP4
IP12
X
0
1
D4
IP4
D4
OP11
OP3
IP11
Blink Phase Registers
IP3
D3
D3
FUNCTION
Disabled
Enabled
BLINK
OP10
IP10
OP2
IP2
D2
D2
OP1
OP9
Blink phase 0
Blink phase 0
Blink phase 1
IP1
IP9
REGISTERS
D1
D1
OUTPUT
registers
registers
registers
USED
OP0
OP8
IP0
IP8
D0
D0