ST6209CM6/SWD View Datasheet(PDF) - STMicroelectronics

Part Name

Description

Manufacturer

ST6209CM6/SWD

8-BIT MCUs WITH A/D CONVERTER, TWO TIMERS, OSCILLATOR SAFEGUARD & SAFE RESET

STMicroelectronics 

ST6208C/ST6209C/ST6210C/ST6220C

8-BIT TIMER (Cont’d)

9.2.4.2 Event counter mode

(TOUT = “0”, DOUT = “0”)

In this mode, the TIMER pin is the input clock of

the Timer prescaler which is decremented on eve-

ry rising edge of the input clock (allowing event

count). See Figure 30 and Figure 31.

This mode is selected by clearing the TOUT bit in

the TSCR register (i.e. as input) and clearing the

DOUT bit.

Note: In this mode, if the TIMER pin is multi-

plexed, the corresponding port control bits have to

be set in input with pull-up configuration.

Figure 30. fTIMER Clock in Event Counter Mode

low-to-high TMZ bit transition is used to latch the

DOUT bit in the TSCR and, if the TOUT bit is set,

DOUT is transferred to the TIMER pin. This oper-

ating mode allows external signal generation on

the TIMER pin. See Figure 33.

This mode is selected by setting the TOUT bit in

the TSCR register (i.e. as output) and setting the

DOUT bit to output a high level or clearing the

DOUT bit to output a low level.

Note: As soon as the TOUT bit is set, The timer

pin is configured as output push-pull regardless of

the corresponding I/O port control registers setting

(if the TIMER pin is multiplexed).

Figure 32. Output Mode Control

TIMER

fPRESCALER

Figure 31. Event Counter Mode Operation

COUNTER VALUE

XX1 VALUE 1

XX2

TIMER PIN

VALUE 2

TI MER

LATCH

TMZ

TOUT DOUT

Figure 33. Output Mode Operation

Counter

FFh

9.2.4.3 Output mode

(TOUT = “1”, DOUT = “data out”)

In Output mode, the TIMER pin is connected to the

DOUT latch, hence the Timer prescaler is clocked

by theprescaler clock input (fINT/12). See Figure32.

The user can select the prescaler division ratio us-

ing the PS[2:0] bits in the TSCR register. When

TCR decrements to zero, it sets the TMZ bit in the

TSCR. The TMZ bit can be tested under program

control to perform a timer function whenever it

goes high and has to be cleared by the user. The

TIMER PIN

1

At each zero event

DOUT has to be

copied to the TIMER

pin

1st downcount:

Default output value is 0

49/105

1

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