Intel 386 Manual do Utilizador descarregar pdf (Página 274)

100

101

10-31

TIMER/COUNTER UNIT

The read-back command can latch the count and status of multiple counters. This single com-

mand is functionally equivalent to several counter-latch commands, one for each counter latched.

Each counter's latched count and status is held until it is read or until you reconfigure the counter.

A counter’s latched count or status is automatically unlatched when read, but other counters’

latched values remain latched until they are read.

After latching a counter’s status and count with a read-back command, reading TMRn accesses

its status format (Figure 10-30). Reading TMRn again accesses its read format. When both the

count and status of a counter are latched, the first read of TMRn indicates the counter’s status and

the next one or two reads (depending on the counter’s read selection) indicate the counter’s count.

Subsequent reads return unlatched count values. When only the count of a counter is latched, then

the first one or two reads of TMRn return the counter’s count. When the counter is programmed

for the two-byte read selection, you must read two bytes.

1 2 ... 269 270 271 272 273 274 275 276 277 278 279 ... 690 691

Comentários a estes Manuais

Sem comentários

Intel 386 Manual do Utilizador Página 274

Comentários a estes Manuais

Manuais e produtos relacionados com Hardware Intel 386