MAX7316 Maxim, MAX7316 Datasheet - Page 15

• Manufacturer Part Number: MAX7316
• Description: The MAX7316 I²C/SMBus™-compatible serial interfaced peripheral provides microprocessors with eight additional I/O ports plus one output-only port and one input-only port
• Manufacturer: Maxim

Table 5. Ports Configuration Register
Table 6. Input Ports Register
Table 7. Blink Logic
The MAX7316 can be configured to provide any combi-
nation of PWM outputs and glitch-free logic outputs.
Each PWM output has an individual 4-bit intensity con-
trol (Table 14). When all outputs are to be used with the
same PWM setting, the outputs can be controlled
together instead using the global intensity control
(Table 13). Table 10 shows how to set up the MAX7316
to suit a particular application.
The PWM control uses a 240-step PWM period, divided
into 15 master intensity timeslots. Each master intensity
timeslot is divided further into 16 PWM cycles (Figure 12).
The master intensity operates as a gate, allowing the indi-
vidual output settings to be enabled from 1 to 15 timeslots
per PWM period (Figures 13, 14, 15) (Table 13).
Each output’s individual 4-bit intensity control only
operates during the number of timeslots gated by the
master intensity. The individual controls provide 16
intensity settings from 1/16 through 16/16 (Table 14).
BLINK ENABLE
Control, Interrupt, and Hot-Insertion Protection
FLAG E
Read back ports configuration
0
1
(1 = input, 0 = output)
Ports configuration
Read input ports
REGISTER
REGISTER
______________________________________________________________________________________
10-Port I/O Expander with LED Intensity
BLINK FLIP
FLAG B
X
0
0
1
1
BLINK INPUT
R/W
R/W
PIN
0
1
1
X
0
1
0
1
PWM Timing
ADDRESS
ADDRESS
CODE
CODE
(HEX)
(HEX)
0x06
0x00
BLINK FLIP FLAG
BLINK INPUT PIN
EXOR
OP7
IP7
D7
D7
X
0
1
1
0
Figures 16, 17, and 18 show examples of individual
intensity control settings. The highest value an individ-
ual or global setting can be set to is 16/16. This setting
forces the output to ignore the master control, and fol-
low the logic level set by the appropriate blink phase
register bit. The output becomes a glitch-free static out-
put with no PWM.
When blink is disabled (Table 7), the blink phase 0 reg-
ister specifies each output’s logic level during the PWM
on-time (Table 8). The effect of setting an output’s blink
phase 0 register bit to 0 or 1 is shown in Table 11. With
its output bit set to zero, an LED can be controlled with
16 intensity settings from 1/16th duty through fully on,
but cannot be turned fully off using the PWM intensity
control. With its output bit set to 1, an LED can be con-
trolled with 16 intensity settings from fully off through
15/16th duty.
Using PWM Intensity Controls with Blink Disabled
OP6
IP6
D6
D6
BLINK FUNCTION
OP5
IP5
D5
D5
Disabled
Enabled
REGISTER DATA
REGISTER DATA
OP4
IP4
D4
D4
OP3
IP3
D3
D3
OUTPUT REGISTERS USED
Blink phase 0 register
Blink phase 0 register
Blink phase 1 register
Blink phase 1 register
Blink phase 0 register
OP2
IP2
D2
D2
OP1
IP1
D1
D1
OP0
IP0
D0
D0
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