gc80c510 CORERIVER Semiconductor, gc80c510 Datasheet - Page 35

• Manufacturer Part Number: gc80c510
• Description: Eprom/rom 8-bit Turbo Microcontrollers
• Manufacturer: CORERIVER Semiconductor

6.2.1.2 PORT 1
MiDAS1.1 Family
P1[2] is a chip reset signal input (RESETB). The pull-up of P[0] and P[1] is OFF and P[2] has no pull-up.
In addition, Port 1 can be configured as the following modes using P1DIR, P1SEL, P1TYPE, ALTSEL
register.
PMR register.
[How to control the XTAL1 (P1[0]) and XTAL2 (P1[1]) as general I/O pins]
(IOXEN flag) to “1”. Then, P1[0] and P1[1] are configured as general I/O pins. And you should set
PMR[3] (XTOFF flag) to “1”.
disable the internal amplifier for crystal between these two pins. Refer to the below figure.
[How to control the RESETB (P1[2]) as I/O pin]
Then, P1[2] is configured as general I/O pin. Note that retain “1” at P1[2] pin until this RESETB pin is
configured as general I/O pin. If you do not that, MCU remains at reset mode.
[How to control the P1 input / output mode]
of P1[0], P1[1], and P1[2] is input mode. To configure the bit of the P1 to output mode, set to the bit of
the P1DIR register to “0” (0 = Output, 1 = Input (Default)).
[How to control the P1 pull-up ON/OFF]
After reset, the port 1 configuration is that P1[0] and P1[1] is crystal input/output (XTAL1/XTAL2) and
Port 1 has the following configuration modes in according to P1DIR, P1SEL, P1TYPE, ALTSEL, and
If you want to use XTAL1 (P1[0]) and XTAL2 (P1[1]) as general I/O pins, you should set ALTSEL[7]
In other words, to use the general I/O pins, you should set P1[0] and P1[1] as general I/O pins and
If you want to use RESETB as general I/O pin, you should set ALTSEL[6] (IORSTEN flag) to “1”.
The initial value of P1DIR (Port 1 Input/Output Control) register is *****111. This means that the mode
The initial value of P0SEL (Port 1 Pull-up Control) register is ******11. This means that the pull-up of
Input / Output mode controlled by P1DIR (Default = ******11, Input mode)
General I/O enable by ALTSEL[7] (IOXEN, Default (= 0) is not general I/O for P1[0] and P1[1]),
ALTSEL[6] (IORSTEN, Default (=0) is not general I/O for P1[2]), and PMR[3] (XTOFF, Default
(=0) does not disable the internal amplifier for external crystal).
Push-pull / Open-drain output type of P1[0] and P1[1] controlled by P1TYPE
(Default = ******00, Push-pull output type). The P1[2] is only the open-drain output type.
Pull-up ON / OFF controlled by P1SEL (Default = ******00, Pull-up OFF)
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