Intel mcs-48 manual ~=- J~~====~

8031/8051/8751

GATE	COUNTER/TIMER RUN	INTERRUPT REQUEST
TIMERI COUNTER 0 IN MODE 3
		PULSE TO
	COUNTER 1	SERIAL PORT

MODE 0: S-BIT TIMER WITH PRESCALERI 8-BIT COUNTER WITH PRESCALER

MODE 1: 16-BIT TIMER/COUNTER

MODE 2: S-BIT AUTO-RELOAD TIC

MODE 3: PREVENTS INCREMENTING OF TIC 1

l~:=-__J:~~====~[)	COUNTER 0
	-----------.j8-BITTIMER(THO)

Figure 2.5.8 Timer/Counter 1 Control and Status Flag Circuitry

,-------------~N;,;T;;;--I

I	, --------- ,	INTERRUPT
I		r ----- *iU___...,.......___J-----.--~~~~SMIT
I
I
I
I
I
I
L		L-_--_--_--_----_--_--_----_--.....I--'-~;~:IVE

Figure 2.6.A Serial Port-Synchronous Mode 0

.10 OR 11 BIT FRAME

•BAUD RATE

GENERATION FROM OSCILLATOR OR TIMER 1

•ADDRESS FRAME RECOGNITION

CRYSTAL

OSCILLATOR

TIMER 1

OVERFLOW

I -	- - - - -	- - - - ~R~S;;"T-;; - ----1
I	, . ---------- ,	INTERRUPT
I		t-____..,-.~~~~SMIT
I		4 -__-,..,___'"

I

I

I

I

I

RECEIVER

=:;-;=;-:;:=-:;;;=-=:;-;;=I::;N=T=ER;:-R=U:;:P~T======c;;;;If__-~~i!1VE

Figure 2.6.8 Serial Port-UART Modes 1, 2, and 3

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