146CHAPTER 6 PORT FUNCTIONS6.2.8 Port 6Port 6 is an 8-bit input/output port with output latch. P60 to P67 pins can specify the input mode/output mode in1-bit units with the port mode register 6 (PM6).This port has pull-up resistor options as shown below. However, the option specification method differs dependingon the port pin and the device version.Table 6-4. Pull-up Resistor Options for Port 6Higher 4 bits (P64 to P67) Lower 4 bits (P60 to P63)Mask ROM version Internal pull-up resistors can be specified Internal mask-option pull-up resistors can beby setting PUO6 in 4-bit units. specified bitwise.PROM version No pull-up resistor optionsPUO6 : Bit 6 of the pull-up resistor option register L (PUOL)Pins P60 to P63 can drive LEDs directly.Dual-functions include the control signal output function in external memory expansion mode.RESET input sets port 6 to input mode.Figures 6-13 and 6-14 show block diagrams of port 6.Cautions 1. When external wait is not used in external memory expansion mode, P66 can be used asan input/output port.2. When the low level is input to the P60 to P63 pins, the leakage current that flows througheach of these pins depends on the following conditions:[Mask ROM version]• When a pull-up resistor is connected,–3μA (max.)• When a pull-up resistor is not connected,–200μA (max.) ........ for 1.5 clock cycles during which a read instruction is executed toport 6 (P6) or port mode register 6 (PM6) (It is assumed that no waitcycles are inserted.)–3μA (max.) ............ during periods other than the above[PROM version]• When a pull-up resistor is not connected,–200μA (max.) ........ for 1.5 clock cycles during which a read instruction is executed toport 6 (P6) or port mode register 6 (PM6) (It is assumed that no waitcycles are inserted.)–3μA (max.) ............ during periods other than the above
