S7760A Datasheet, PDF (13/54 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.2.0_01
S-7760A
 Command
1. Reload
This is a 1-byte command. Users can reload by inputting either of R / W in 0/1. When inputting this command, the
data corresponding to the E²PROM is loaded to the register. After completing reload, (if the condition is satisfied), the
timer action starts. The reload command is not accepted during the timer action (from its start to the final invert of
output). Refer to “ Condition to Start Timer” regarding details.
2. Switching access to register/E²PROM
This is a 1-byte command. The mode is in “register access mode” when this command is R / W = 0, “E²PROM
access mode” when this command is R / W = 1. The register corresponding to the E²PROM is the one to be
reloaded. In register access mode, only the register is rewritten, the E²PROM maintains the prior data. In “E²PROM
access mode”, both data in the register and E²PROM is rewritten.
3. Timer enable register
A timer enable register is a 4-bit register for Write only (it sends back FFh during Read). By setting each bit in the
register in “1”, an oscillation circuit starts, output from the lower 4ch ports (DO3 to 0) invert after the elapsed period
which is set by a timer setting register. This action is called “timer action”. This timer action starts at the point when
receiving TEN0 which is LSB in the register. The bit automatically goes back in “0” after writing “1” in the timer enable
register. Users cannot write in this register during the timer action (from the start to the final invert of output). This
register is not the one to be reloaded, thus it does not have the data which corresponds to the E²PROM. The option is
available for the condition to start a timer; Condition AND with TIMEN = High, depending on the option. Refer to “
Condition to Start Timer” regarding details.
B7
B6
B5
MSB
－
－
－
B4
B3
B2
B1
B0
－
TEN 3 TEN 2 TEN 1 TEN 0
LSB
W
W
W
W
W
W
W
W
0 : Disable to invert output
1 : Enable to invert output
Figure 14 Timer Enable Register
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