COP8SG Datasheet, PDF (15/62 Pages) National Semiconductor (TI) – 8-Bit CMOS ROM Based and OTP Microcontrollers with 8k to 32k Memory, Two Comparators and USART

4.0 Pin Descriptions (Continued)
Note: For compatibility with existing software written for COP888xG devices
and with existing Mask ROM devices, a read of the Port I input pins
(address xxD7) will return the same data as reading the Port F input
pins (address xx96). It is recommended new applications which will go
to production with the COP8SGx use the Port F addresses. Note that
compatible ROM devices contains the input only Port I instead of the
bi-directional Port F.
Port D is an 8-bit output port that is preset high when RESET
goes low. The user can tie two or more D port outputs
(except D2) together in order to get a higher drive.
Note: Care must be exercised with the D2 pin operation. At RESET, the
external loads on this pin must ensure that the output voltages stay
above 0.7 V_CC to prevent the chip from entering special modes. Also
keep the external loading on D2 to less than 1000 pF.
10131712
FIGURE 5. I/O Port Configurations — Output Mode
FIGURE 4. I/O Port Configurations
10131710
10131711
FIGURE 6. I/O Port Configurations — Input Mode
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