UPD784938 Datasheet, PDF (169/733 Pages) NEC – 16-Bit Single-Chip Microcontrollers

CHAPTER 6 PORT FUNCTIONS
6.8 Port 6
Port 6 is an 8-bit input/output port with an output latch. P60 to P67 incorporate a software programmable pull-up resistor.
In addition to its function as a port, port 6 also has various alternate-function control signal pin functions as shown in Table
6-8. Operations as control pins are performed by the respective function operations.
When RESET is input, P60 to P67 are set as input port pins (output high-impedance state), and the output latch contents
are undefined.
Table 6-8. Port 6 Operation Modes
Pin Name
P60 to P63
P64
P65
P66
P67
Port Mode
Input/output ports
Control Signal Input/
Output Mode
A16 to A19 outputs
RD output
WR output
WAIT input
HLDRQ input
HLDAK output
REFRQ output
Operation to Operate as Control Pins
Specified by bits MM3 to MM0 of the MM in 2-bit units
External memory expansion mode is specified by bits MM3 to
MM0 of the MM
Specified by bits PWn1 & PWn0 (n = 0 to 7) of the PWC1 &
PWC2 or setting P66 in the input mode
Bus hold enabled by the HLDE bit of the HLDM
Set (to 1) the RFEN bit of the RFM
Preliminary User’s Manual U13987EJ1V0UM00
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