Toshiba TLCS-90 Series Data Book page 24

TOSHIBA TMP 8048A/TMP 8035A, TMP 8049A/TMP B039A
If the pulse is generated externally the reset pin must be held at ground
(~O.8V)
for at least lOmS after the power supply is within tolerance •
. Reset performs the following functions within the chip:
Sets PC to Zero.
Sets Stack Pointer to Zero.
Selects Register Bank
O.
Selects Memory Bank
O.
(i)
(ii)
( iii)
(iv)
(v)
( vi)
(vii)
(vi ii)
(ix)
(x)
(xi)
Sets BUS (DBO - DB?) to high impedance state. (Except when EA=5V)
Sets Ports 1 and 2 to input mode.
Disables interrupts (timer and external).
Stops Timer.
Clears Timer Flag.
Clears FO and Fl.
Disables clock output from TO.
(10) Oscillator Circuit
TMP8048A
can be operated by the external clock input in addition to
crystal oscillator as shown below.
+5V
XTAL 1
XTAL 1
XTAL Z
XTAL
2
----~h---~----y
(a) Crystal Parameters and External Capacitance
The frequency of the oscillator will be calculated from the following
formula.
f -
(1+CO/2{CL+C»/2n~
Load Capacitance~L
CL=(Cl+Cfl)(C2+Cf2)/«Cl+Cfl)+(C2+Cf2»
Cfl Input Capacitance (4pF Typ.)+Stray Capacitance (less than SpF)
Cf2 : Output Capacitance(6pF Typ.)+Stray Capacitance (less than SpF)
MCU48-14