HD64F3048VTF8 Datasheet, PDF (308/903 Pages) Renesas Technology Corp – Hardware Manual Renesas 8-Bit Single-Chip

Section 9 I/O Ports
9.7 Port 6
9.7.1 Overview
Port 6 is a 7-bit input/output port that is also used for input and output of bus control signals
(LWR, HWR, RD, AS, BACK, BREQ, and WAIT). When DRAM is connected to area 3, LWR,
HWR, and RD also function as LW, UW, and CAS, or LCAS, UCAS, and WE, respectively. For
details see section 7, Refresh Controller.
Figure 9.6 shows the pin configuration of port 6. In modes 1 to 6 (expanded modes) the pin
functions are LWR, HWR, RD, AS, P6₂/BACK, P6₁/BREQ, and P6₀/WAIT. See table 9.11 for the
method of selecting the pin states. In mode 7 (single-chip mode) port 6 is a generic input/output
port.
Pins in port 6 can drive one TTL load and a 30-pF capacitive load. They can also drive a
darlington transistor pair.
Port 6
Port 6 pins
P6 ₆ / LWR
P6 ₅ / HWR
P6 ₄ / RD
P6 ₃ / AS
P6 ₂ / BACK
P6 ₁ / BREQ
P6 ₀ / WAIT
Modes 1 to 6
(expanded modes)
LWR (output)
HWR (output)
RD (output)
AS (output)
P6 ₂ (input/output)/ BACK (output)
P6 ₁ (input/output)/ BREQ (input)
P6 ₀ (input/output)/ WAIT (input)
Mode 7
(single-chip mode)
P6 ₆ (input/output)
P6 ₅ (input/output)
P6 ₄ (input/output)
P6 ₃ (input/output)
P6 ₂ (input/output)
P6 ₁ (input/output)
P6 ₀ (input/output)
Figure 9.6 Port 6 Pin Configuration
Rev. 3.00 Sep 27, 2006 page 280 of 872
REJ09B0325-0300