mc68331cpv20b1 Freescale Semiconductor, Inc, mc68331cpv20b1 Datasheet - Page 228

• Manufacturer Part Number: mc68331cpv20b1
• Description: Mc68331 32 Bit Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

D
BME — Bus Monitor External Enable
BMT[1:0] — Bus Monitor Timing
D.3.13 PICR — Periodic Interrupt Control Register
PIRQL[2:0] — Periodic Interrupt Request Level
PIV[7:0] — Periodic Interrupt Vector
D.3.14 PITR — Periodic Interrupt Timer Register
PTP — Periodic Timer Prescaler Control
PITM[7:0] — Periodic Interrupt Timing Modulus
D-20
15
15
0
0
0
0
This field selects bus monitor time-out period.
Contains information concerning periodic interrupt priority and vectoring. PICR[10:0]
can be read or written at any time. PICR[15:11] are unimplemented and always return
zero.
This field determines the priority of periodic interrupt requests.
The bits of this field contain the periodic interrupt vector number supplied by the SIM
when the CPU acknowledges an interrupt request.
Contains the count value for the periodic timer. This register can be read or written at
any time.
This is the 8-bit timing modulus used to determine periodic interrupt rate. Use the fol-
lowing expression to calculate timer period.
RESET:
RESET:
0 = Disable bus monitor function for an internal to external bus cycle.
1 = Enable bus monitor function for an internal to external bus cycle.
0 = Periodic timer clock not prescaled
1 = Periodic timer clock prescaled by a value of 512
14
14
0
0
0
0
13
13
0
0
0
0
12
12
0
0
0
0
Freescale Semiconductor, Inc.
11
11
For More Information On This Product,
0
0
0
0
BMT
Table D-7 Bus Monitor Period
00
01
10
11
10
10
0
0
0
Go to: www.freescale.com
REGISTER SUMMARY
PIRQL
0
9
0
0
Bus Monitor Time-out Period
MODCLK
64 System Clocks
32 System Clocks
16 System Clocks
8
0
8 System Clocks
PTP
8
7
0
7
0
0
0
0
0
0
PIV
0
PITM
1
0
USER’S MANUAL
1
0
$YFFA22
$YFFA24
1
MC68331
0
0
1
0
0