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2 periodic interrupt timer count register (pitc), Periodic interrupt timer count register (pitc) -43, Piscr field descriptions -43 – Motorola MPC8260 User Manual

Page 181: Table 4-21 describes piscr þelds

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4-43

MPC8260 PowerQUICC II UserÕs Manual

MOTOROLA

Part II. ConÞguration and Reset

Table 4-21 describes PISCR Þelds.

4.3.3.2 Periodic Interrupt Timer Count Register (PITC)

The periodic interrupt timer count register (PITC), shown in Figure 4-39, contains the 16
bits to be loaded in a modulus counter.

Table 4-21. PISCR Field Descriptions

Bits

Name

Description

0Р7

С

Reserved, should be cleared.

8

PS

Periodic interrupt status. Asserted if the PIT issues an interrupt. The PIT issues an interrupt after the
modulus counter counts to zero. The PS bit can be negated by writing a one to PS. A write of zero has
no effect on this bit.

9Р12

С

Reserved, should be cleared.

13

PIE

Periodic interrupt enable. If PIE = 1, the periodic interrupt timer generates an interrupt when PS = 1.

14

PTF

Periodic interrupt frequency. The input clock to the periodic interrupt timer may be either 4 MHz or
32 KHz. The user should set the PTF bit according to the frequency of this clock.
0 The input clock to the periodic interrupt timer is 4 MHz.
1 The input clock to the periodic interrupt timer is 32 KHz.
See Section 4.1.2, ÒTimers Clock,Ó for further details

15

PTE

Periodic timer enable. This bit controls the counting of the periodic interrupt timer. When the timer is
disabled, it maintains its old value. When the counter is enabled, it continues counting using the
previous value.
0 Disable counter.
1 Enable counter

Bits

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

Field

PITC

Reset

0000_0000_0000_0000

R/W

R/W

Addr

0x10244

Bits

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

Field

Ñ

Reset

0000_0000_0000_0000

R/W

R/W

Addr

0x10246

Figure 4-39. Periodic interrupt Timer Count Register (PITC)