ez80f91 ZiLOG Semiconductor, ez80f91 Datasheet - Page 63

• Manufacturer Part Number: ez80f91
• Description: Ez80 Acclaimplus!? Connectivity Assp Ez80f91 Assp
• Manufacturer: ZiLOG Semiconductor

Table 7. Port x Data Registers
(PA_DR = 0096h, PB_DR = 009Ah, PC_DR = 009Eh, PD_DR = 00A2h)
Table 8. Port x Data Direction Registers
(PA_DDR = 0097h, PB_DDR = 009Bh, PC_DDR = 009Fh, PD_DDR = 00A3h)
PS027001-0707
Bit
Reset
CPU Access
Note: X = Undefined; R/W = Read/Write.
Bit
Reset
CPU Access
Note: R/W = Read/Write.
GPIO Control Registers
Edge triggered interrupts are cleared by writing 1 to the corresponding bit of the Px_ALT0
register. For example, if PD4 has been set up to generate an edge triggered interrupt, the
interrupt is cleared by writing a 1 to Px_ALT0[4].
Each GPIO port has four registers that controls its operation. The operating mode of each
bit within a port is selected by writing to the corresponding bits of these four registers as
shown in
Data Direction register(Px_DDR), Port Alternate register 1(PX_ALT1), and Port Alternate
register 2(Px_ALT2). In addition to these four control registers, each port has a Port
Alternate register 0(Px_ALT0), which is used for clearing edge triggered interrupts.
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
reading from the Port x Data registers always returns the sampled current value of the
corresponding pins. When the port pins are configured for edge triggered interrupts or
level-sensitive interrupts, the value written to the Port x Data register bit selects the
interrupt edge or interrupt level (for more details on GPIO mode selection, see
page 50).
Port x Data Direction Registers
In conjunction with the other GPIO Control registers, the Port x Data Direction registers
(see
mode selection, see
Table
Table 6
R/W
R/W
8) control the operating modes of the GPIO port pins. For more details on GPIO
X
7
7
1
on page 50. These four registers are Port Data register(Px_DR), Port
R/W
R/W
X
6
6
1
Table 6
Table
R/W
R/W
X
5
5
1
on page 50.
7) is driven on the corresponding pins. In all modes,
R/W
R/W
X
4
4
1
R/W
R/W
X
3
3
1
R/W
R/W
X
2
2
1
R/W
R/W
X
1
1
1
General Purpose Input/Output
Product Specification
R/W
R/W
X
0
0
1
eZ80F91 ASSP
Table 6
on
55