AMD Am186TMER, Am188TMER 4.2 INITIALIZATION AND PROCESSOR RESET

Peripheral Control Block
4-8
Bits 2–0: Clock Divisor Select (F2–F0)—Controls the division factor when Power-Save
mode is enabled. Allowable values are as follows:
4.2 INITIALIZATION AND PROCESSOR RESET
Processor initialization or startup is accomplished by driving the RES input pin Low. RES
must be Low during power-up to ensure proper device initialization. RES forces the
Am186ER and Am188ER microcontrollers to terminate all execution and local bus activity.
No instruction or bus activity occurs as long as RES is active.
After RES is deasserted and an internal processing interval elapses, the microcontroller
begins execution with the instruction at physical location FFFF0h. RES also sets some
registers to predefined values as shown in Table 4-2.
F2 F1 F0 Divider Factor
000 Divide by 1 (20)
001 Divide by 2 (21)
010 Divide by 4 (22)
011 Divide by 8 (23)
100 Divide by 16 (24)
101 Divide by 32 (25)
110 Divide by 64 (26)
111 Divide by 128 (27)