Rainbow-electronics ATmega128L Manual de usuario descargar pdf (Pagina 68)

ATmega128(L)

2467B–09/01

• Bit 2 - PUD: Pull-up disable

When this bit is written to one, the pull-ups in the I/O ports are disabled even if the DDxn

and PORTxn registers are configured to enable the pull-ups ({DDxn, PORTxn} = 0b01).

See

“Configuring the Pin” on page 61 for more details about this feature.

Alternate Functions of Port A The Port A has an alternate function as the address low byte and data lines for the

External Memory Interface.

Table 28 and Table 29 relates the alternate functions of Port A to the overriding signals

shown in

Figure 32 on page 66.

Note: 1. ADA is short for ADdress Active and represents the time when address is output. See

“External Memory Interface” on page 24 for details.

Table 27. Port A Pins Alternate Functions

Port Pin Alternate Function

PA7 AD7 (External memory interface address and data bit 7)

PA6 AD6 (External memory interface address and data bit 6)

PA5 AD5 (External memory interface address and data bit 5)

PA4 AD4 (External memory interface address and data bit 4)

PA3 AD3 (External memory interface address and data bit 3)

PA2 AD2 (External memory interface address and data bit 2)

PA1 AD1 (External memory interface address and data bit 1)

PA0 AD0 (External memory interface address and data bit 0)

Table 28. Overriding Signals for Alternate Functions in PA7..PA4

Signal

Name PA7/AD7 PA6/AD6 PA5/AD5 PA4/AD4

PUOE SRE SRE SRE SRE

PUOV ~(WR | ADA

(1)

) •

PORTA7 • PUD

~(WR | ADA) •

PORTA6 • PUD

~(WR | ADA) •

PORTA5 • PUD

~(WR | ADA) •

PORTA4 • PUD

DDOE SRE SRE SRE SRE

DDOV WR | ADA WR | ADA WR | ADA WR | ADA

PVOE SRE SRE SRE SRE

PVOV A7 • ADA | D7

OUTPUT • WR

A6 • ADA | D6

OUTPUT • WR

A5 • ADA | D5

OUTPUT • WR

A4 • ADA | D4

OUTPUT • WR

DIEOE0000

DIEOV0000

DID7 INPUTD6 INPUTD5 INPUTD4 INPUT

AIO ––––

1 2 ... 63 64 65 66 67 68 69 70 71 72 73 ... 330 331

Comentarios a estos manuales

Sin comentarios

Rainbow-electronics ATmega128L Manual de usuario Pagina 68

Comentarios a estos manuales

Relacionado con productos y manuales para Sensores Rainbow-electronics ATmega128L