eZ80L92 MCU
Product Specification
42
edge-triggered interrupt, writing a 1 to that pin’s Port x Data register causes a reset of the
edge-detected interrupt. You must set the bit in the Port x Data register to 1 before entering
either single or dual edge-triggered interrupt mode for that port pin.
When configured for dual edge-triggered interrupt mode (GPIO Mode 6), both a rising
and a falling edge on the pin cause an interrupt request to be sent to the eZ80 CPU.
When configured for single edge-triggered interrupt mode (GPIO Mode 9), the value in
the Port x Data register determines if a positive or negative edge causes an interrupt
request. A 0 in the Port x Data register bit sets the selected pin to generate an interrupt
request for falling edges. A 1 in the Port x Data register bit sets the selected pin to generate
an interrupt request for rising edges.
GPIO Control Registers
The 12 GPIO Control Registers operate in groups of four with a set for each Port (Ports B,
C, and D). Each GPIO port features a Port Data register, Port Data Direction register, Port
Alternate register 1, and Port Alternate register 2.
Port x Data Registers
When the port pins are configured for one of the output modes, the data written to the
Port x Data Registers (see Table 7) are driven on the corresponding pins. In all modes,
reading from the Port x Data registers always returns the current sampled value of the
corresponding pins. When the port pins are configured as edge-triggered interrupt sources,
writing 1 to the corresponding bit in the Port x Data register clears the interrupt signal that
is sent to the eZ80 CPU. When the port pins are configured for edge-selectable interrupts
or level-sensitive interrupts, the value written to the Port x Data register bit selects the
interrupt edge or interrupt level. See Table 6.
Table 7. Port x Data Registers (PB_DR = 009Ah, PC_DR = 009Eh, PD_DR =
00A2h)
Bit
7
X
6
X
5
X
4
X
3
X
2
X
1
X
0
X
Reset
CPU Access
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Note: X = Undefined; R/W = Read/Write.
PS013015-0316
General-Purpose Input/Output
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