ST72314J/N,

Stresses above those listed as "absolute maxi-mum ratings" may cause permanent damage to the device. This is a stress rating only and func- tional operation of the device under these condi-tions is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability.

Each port has 2 main registers of the ST72314J/N,:
Data Register (DR)
Data Direction Register (DDR)
and one optional register:
Option Register (OR)
Each I/O pin of the ST72314J/N, may be programmed using the corre- sponding register bits in the DDR and OR regis- ters: bit X corresponding to pin X of the port. The same correspondence is used for the DR register. The following description takes into account the OR register, (for specific ports which do not pro-vide this register refer to the I/O Port Implementa-tion section). The generic I/O block diagram is shown in Figure 26