S-7750C Datasheet, PDF (16/44 Pages) Seiko Instruments Inc – PROGRAMMABLE PORT CONTROLLER (PORT EXPANDER WITH BUILT-IN E2PROM CIRCUIT)

PROGRAMMABLE PORT CONTROLLER (PORT EXPANDER WITH BUILT-IN E²PROM CIRCUIT)
S-7750C
Rev.1.1_00
„ Condition to start timer, Port Output and Register
The timer action starts when either condition is satisfied. However, if “00h” is set in the timer setting register, timer action
does not start.
1. When power-on (the TIMEN pin is in “H”)
2. When the TIMEN pin changes from “L” to “H”
3. While the TIMEN pin is in “H”, users do Write any commands other than “00h” in the timer enable register.
4. While the TIMEN pin is in “H”, the power supply voltage exceeds the level of release voltage of the circuit for
prevention malfunction by low voltage (2.05 V typ.).
5. While the TIMEN pin is in “H”, users set the reload command.
Starting a timer action makes output from the DO7 to DO0 pins inverted after the period set by a timer has elapsed.
Figure 18 shows the timing chart of 1, 2, and 3. Set V_CCH ≥ 2.5V when raising VCCH and TIMEN simultaneously.
Power supply voltage
V_CCH / V_CCL
Signal of low power
supply voltage
detection
TIMEN pin
Data loading
Oscillation circuit EN
2.05 V Typ.
Start of timer action due to power-on
Start of timer action by setting
TIMEN pin “L” → “H”
Start of timer action by
Write in timer enable register
DO1 pin
(When E²PROM
CTR1 = 0)
CTR1 register
(When E²PROM
CTR1 = 0)
Delay time by timer setting for DO1
Time out
Delay time by timer setting for DO1
Time out
Delay time by timer setting for DO1
Time out
Reload starts
*1
*1
*1
DO0 pin
(When E²PROM
CTR1 = 1)
CTR0 register
(When E²PROM
CTR1 = 1)
Delay time by timer setting for DO0
Delay time by timer setting for DO0
Delay time by timer setting for DO0
Reload starts
*1
*1
*1
Period to define data ^*2
*1. The value of control port register does not change even if the port output is inverted by timer action.
*2. A period to define data is; the loading period from E²PROM + the period to stabilize the output from DO7 to DO0 pin =
within 100 µs.
Figure 18 Example of Condition to Start Timer Action 1
16
Seiko Instruments Inc.