EM78862C View Datasheet(PDF) - ELAN Microelectronics
Part Name
Description
MFG CO.
'EM78862C' PDF : 42 Pages View PDF
EM78862C
8-Bit RISC Type Microprocessor
6.4 I/O Ports
The I/O registers (Ports 7, 8, and 9), are bi-directional tri-state I/O ports. Port 7 can be
pulled-high internally by software. Furthermore, each I/O pin can be defined as "input"
or "output" pin by the I/O control registers (IOC7 ~ IOC9). The I/O registers and I/O
control registers are both readable and writable. The I/O interface circuits are shown in
Fig. 9 below.
Fig. 9 Ports 7, 8, & 9 I/O Port and I/O Control Register Circuit
6.5 RESET
RESET will occur during any of the following conditions:
Power on reset
WDT timeout (if WDT is enabled during SLEEP, GREEN, or NORMAL mode)
RESET pin pull low
Once a RESET occurs, the following functions are performed:
The oscillator will continue running and the Program Counter (R2) is set to all "0"
All I/O port pins are configured to input mode (high-impedance state)
The TCC/Watchdog timer and prescaler are cleared and Watchdog timer is
disabled
When power is switched on, the upper 3 bits of R3 and the upper 2 bits of R4 are
cleared
The bits of the CONT register are set to all "1"
Product Specification (V2.1) 07.13.2005
(This specification is subject to change without further notice)
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