Specifications

10 EPSON S1C60N04 TECHNICAL MANUAL
CHAPTER 4: PERIPHERAL CIRCUITS AND OPERATION (Input Ports)
4.3 Input Ports (K00–K03)
4.3.1 Configuration of input port
The S1C60N04 has a 4-bit general-purpose input port. Each of the input port pins (K00–K03) has an
internal pull-down resistor. The pull-down resistor can be selected for each bit with the mask option.
Figure 4.3.1.1 shows the configuration of input port.
K0x
VSS
Mask option
Address
VDD
Interrupt
request
Data bus
Fig. 4.3.1.1 Configuration of input port
Selecting "pull-down resistor enabled" with the mask option allows input from a push button, key matrix,
and so forth. When "pull-down resistor disabled" is selected, the port can be used for slide switch input
and interfacing with other LSIs.
4.3.2 Interrupt function
All four input port bits (K00–K03) provide the interrupt function. The conditions for issuing an interrupt
can be set by the software for the four bits. Also, whether to mask the interrupt function can be selected
individually for all four bits by the software. Figure 4.3.2.1 shows the configuration of K00–K03.
Data bus
Address
Interrupt mask
register (EIK)
K0x
Mask option
(K00–K03)
Noise
rejector
Interrupt factor
flag (IK0)
Interrupt
request
Address
Address
Fig. 4.3.2.1 Input interrupt circuit configuration (K00–K03)
The interrupt mask registers (EIK00–EIK03) enable the interrupt mask to be selected individually for
K00–K03. An interrupt occurs when the input value which are not masked change and the interrupt
factor flag (IK0) is set to 1.