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8.9
Port 8
8.9.1
Overview
Port 8 is a 5-bit input/output port that is also used for CS
IRQ
input, and A/D converter ADTRG input. Figure 8.8 shows the pin configuration of port 8.
0
In modes 1 to 5 (expanded modes), port 8 can provide CS
IRQ
input, and ADTRG input. See table 8.14 for the selection of pin functions in expanded
0
modes.
In modes 6 and 7 (single-chip modes), port 8 can provide IRQ
See table 8.15 for the selection of pin functions in single-chip mode.
See section 15, A/D Converter, for a description of the A/D converter's ADTRG input pin.
The IRQ
to IRQ
functions are selected by IER settings, regardless of whether the pin is used for
3
0
input or output. Caution is therefore required. For details see section 5.3.1, External Interrupts.
When DRAM is connected to areas 2 to 5, the CS
pins for each area. For details see section 6.5, DRAM Interface.
Pins in port 8 can drive one TTL load and a 90-pF capacitive load. They can also drive a
darlington transistor pair.
Pins P8
to P8
have Schmitt-trigger inputs.
2
0
to CS
output, RFSH output, IRQ
3
0
to CS
output, RFSH output, IRQ
3
0
to IRQ
3
0
and CS
output pins function as RAS output
3
2
Rev. 4.00 Jan 26, 2006 page 295 of 938
Section 8 I/O Ports
to
3
3
input and ADTRG input.
REJ09B0276-0400
to
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