Z8673312PSG Datasheet, PDF (50/84 Pages) Zilog, Inc. – CMOS Z8 OTP Microcontrollers

CMOS Z8^® OTP Microcontrollers
Product Specification
46
Functional Description
The MCU incorporates the following special functions to enhance the standard Z8 archi-
tecture to provide the user with increased design flexibility.
RESET. The device is reset in one of three ways:
1. Power-On Reset
2. Watchdog Timer
3. Stop Mode Recovery Source
Note: Having the Auto Power-On Reset circuitry built-in, the MCU does not
need to be connected to an external power-on reset circuit. The reset
time is T_POR. The MCU does not re-initialize WDTMR, SMR, P2M,
and P3M registers to their reset values on a Stop Mode Recovery
operation.
Note: The device V_CC must rise up to the operating V_CC specification before
the T_POR expires.
Program Memory. The MCU can address up to 4/8/16 KB of Internal Program Memory
(see Figure 22). The first 12 bytes of program memory are reserved for the interrupt vec-
tors. These locations contain six 16-bit vectors that correspond to the six available inter-
rupts. For EPROM mode, byte 12 (000Ch) to address 4095 (0FFFh)/8191 (1FFFh)/
16384 (3FFFh), consists of programmable EPROM. After reset, the program counter
points at the address 000Ch, which is the starting address of the user program.
In ROMless mode, the Z86E43/743/E44 can address up to 64 KB of External Program
Memory. The ROM/ROMless option is only available on the 44-pin devices.
PS022901-0508
Electrical Characteristics