S-7750C Datasheet, PDF (17/44 Pages) Seiko Instruments Inc – PROGRAMMABLE PORT CONTROLLER (PORT EXPANDER WITH BUILT-IN E2PROM CIRCUIT)

PROGRAMMABLE PORT CONTROLLER (PORT EXPANDER WITH BUILT-IN E²PROM CIRCUIT)
Rev.1.1_00
S-7750C
Figure 19 shows the timing chart of 4 and 5.
In the S-7750C, when the power supply voltage reaches the level of detection voltage of the circuit for prevention
malfunction by low voltage (1.75 V typ.), the DO7 to DO0 pins and the register go in “L”. After that, the power supply
voltage reaches the level of release voltage of the circuit for prevention malfunction by low voltage (2.05 V typ.), data is
loaded to the register from the E²PROM so that the timer action starts. Regarding the circuit for prevention malfunction by
low voltage, refer to “„ Action of Circuit for Prevention Malfunction by Low Voltage”.
When the S-7750C receives the reload command, the register is initialized so that the DO7 to DO0 pins once go in “L”.
When it receives a stop condition, data is loaded to the register from the E²PROM so that the DO7 to DO0 pins output the
default value. At this moment, the timer action starts thus output from DO7 to DO0 pins is inverted after the period set by
timer.
Power supply
voltage
V_CCH / V_CCL
1.75 V Typ.
2.05 V Typ.
Signal of low power
supply voltage
detection
TIMEN pin
Data loading
Oscillation circuit EN
Exceeded the release voltage
of low supply voltage detection
(2.05 V); Timer action starts
Time out
Timer action starts by reloading
Time out
SDA
Start condition
Device code
ACK
Reload instruction
Stop condition
SCL
DO1 pin
(When E²PROM
CTR1 = 0)
CTR1 register
(When E²PROM
CTR1 = 0)
Delay time by timer setting for DO1
Reload starts
*3
*1
Delay time by timer setting for DO1
*2
Reload starts
*1
DO0 pin
(When E²PROM
CTR1 = 1)
CTR0 register
(When E²PROM
CTR1 = 1)
Delay time by timer setting for DO0
Reload starts
*1
*3
Delay time by timer setting for DO0
*2
Reload starts
*1
Period to define data^*4
Period to define data ^*4
*1. The value of control port register does not change even if the port output is inverted by timer action.
*2. Goes in “L” once during S-7750C recognizing the reload command to receiving a stop condition.
*3. Goes in “L” when the power supply voltage reaches the level of the circuit for prevention malfunction by low voltage.
*4. A period to define data is; the loading period from E²PROM + the period to stabilize the DO7 to DO0 pin = within 100 µs.
Figure 19 Example of Condition to Start Timer Action 2
Seiko Instruments Inc.
17