C8051F021 参数 Datasheet PDF下载

C8051F020/1/2/3

23.2.3. High Speed Output Mode

In High Speed Output mode, a module’s associated CEXn pin is toggled each time a match occurs between the PCA

Counter and the module's 16-bit capture/compare register (PCA0CPHn and PCA0CPLn) Setting the TOGn, MATn,

and ECOMn bits in the PCA0CPMn register enables the High-Speed Output mode.

Important Note About Capture/Compare Registers:

When writing a 16-bit value to the PCA0 Capture/Compare

registers, the low byte should always be written first. Writing to PCA0CPLn clears the ECOMn bit to ‘0’; writing to

PCA0CPHn sets ECOMn to ‘1’.

Figure 23.6. PCA High Speed Output Mode Diagram

Write to

PCA0CPLn

Reset

Write to

PCA0CPHn

0

ENB

PCA0CPMn

ENB

1

P

ECCMT

P

E

W

C A A A O

W

C

M

OPP TG

M

C

1

MP N n n

n

F

n

6

n n n

n

x

0 0

0 x

PCA Interrupt

PCA0CN

PCA0CPLn

PCA0CPHn

CC

FR

CCCCC

CCCCC

FFFFF

4 3 2 1 0

Enable

16-bit Comparator

Match

0

1

Toggle

PCA

Timebase

TOGn

0

CEXn

1

Crossbar

Port I/O

PCA0L

PCA0H

Rev. 1.4

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