S7760A Datasheet, PDF (15/54 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
6. DO0 to 3 Timer setting registers
These registers are 8-bit registers which correspond to each port, with these registers, users can set delay time for the
change of output at output ports (DO0 to 3). When delay time is set, its value is a multiple of timer scale. The multiple
is integers 1 to 8. By setting the corresponding bits seen in Figure 17 in “1”, a multiple is selected to determine delay
time. For each port, set only 1-bit in the bit that you set “1”. And if setting all 8 bits in “0”, output is not inverted even if
the condition to start a timer matches.
MSB
B7
B6
B5
B4
B3
B2
B1
B0
LSB
DO0
8×T
7×T
6×T
5×T
4×T
3×T
2×T
1×T
DO1
8×T
7×T
6×T
5×T
4×T
3×T
2×T
1×T
DO2
8×T
7×T
6×T
5×T
4×T
3×T
2×T
1×T
DO3
8×T
7×T
6×T
5×T
4×T
3×T
2×T
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Figure 17 Timer Setting Register DO0 to 3
Figure 17 shows the short-time timer scale setting. In case of a long-time setting, T is LT.
The following options are available for timer setting.
・Using an internal oscillation circuit/Switching the external clock input
・Option setting for delay time (4 types)
(1) When using an internal clock (Typ.)
Option A : (Short-time setting scale, long-time setting scale) = (T, LT) = (5 μs, 320 μs)
Option B : (Short-time setting scale, long-time setting scale) = (T, LT) = (10 μs, 640 μs)
(2) When using an external clock (Period of input clock = T’)
Option A : (Short-time setting scale, long-time setting scale) = (T, LT) = (T’, 64 × T’)
Option B : (Short-time setting scale, long-time setting scale) = (T, LT) = (2 × T’, 128 × T’)
1×T
R/W
15