Добавил:
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз: Предмет: Файл:
Сигнальный МП Motorola DSP56002.pdf
Скачиваний:
22
Добавлен:
26.05.2014
Размер:
2 Мб
Скачать
☆

Freescale Semiconductor, Inc.

Freescale Semiconductor, Inc.

DSP56002 INTERRUPT PRIORITY REGISTER

Note: The difference between Modes 1 and 5 in the DSP56002 and Mode 1 in the DSP56001 may be considered software incompatibility. A DSP56001 program that reloads the internal P: RAM from the Host Port by setting MB-MA = 01 (assuming external pull-up resistor on bit 23 of P:$C000) will not work correctly in the DSP56002. In the DSP56002, the program would trigger a bootstrap from the external EPROM. The solution is to modify the DSP56001 program to set MC-MA = 101.

3.4.7Bootstrap From SCI (Mode 6)

In this mode, the Bootstrap ROM is enabled and the bootstrap program is executed. The internal and/or external program RAM is loaded from the SCI serial interface. The number of program words to load and the starting address must be specified. The SCI bootstrap code expects to receive 3 bytes specifying the number of program words, 3 bytes specifying the address from which to start loading the program words, and then 3 bytes for each program word to be loaded. The number of words, the starting address and the program words are received least significant byte first, followed by the mid-, and then by the most significant byte. After receiving the program words, program execution starts at the address where the first instruction was loaded. The SCI is programmed to work in asynchronous mode with 8 data bits, 1 stop bit, and no parity. The clock source is external and the clock frequency must be 16x the baud rate. After each byte is received, it is echoed back through the SCI transmitter.

3.4.8Reserved (Mode 7)

This mode is reserved for future definition. If selected, the processor defaults to Mode 6.

3.5DSP56002 INTERRUPT PRIORITY REGISTER

Section 7 of the DSP56000 Family Manual describes interrupt (exception) processing in detail. It discusses interrupt sources, interrupt types, and interrupt priority levels (IPL).

Interrupt priority levels for each on-chip peripheral device and for each external interrupt source can be programmed under software control by writing to the interrupt priority register. Level 3 interrupts are nonmaskable, and interrupts of levels 0-2 are maskable.

The DSP56002 Interrupt Priority Register (IPR) configuration is shown in Section Figure 3-4 DSP56002 Interrupt Priority Register (IPR). The starting addresses of interrupt vectors in the DSP56002 are defined as shown in Section Table 3-4 Interrupt Vectors, while the relative priorities of exceptions within the same IPL are defined as shown in

Section Table 3-5 Exception Priorities Within an IPL).

3 - 12 MEMORY MODULES AND OPERATING MODES MOTOROLA

For More Information On This Product, Go to: www.freescale.com

Freescale Semiconductor, Inc.

Freescale Semiconductor, Inc.

DSP56002 PHASE-LOCKED LOOP (PLL) MULTIPLICATION FACTOR

11

10

9

8

7

6

5

4

3

2

1

0

HPL1

HPL0

 

 

 

 

IBL2

IBL1

IBL0

IAL2

IAL1

IAL0

 

 

 

 

 

 

 

 

 

 

 

 

IRQA MODE

IRQB MODE

RESERVED

HOST IPL

23

22

21

20

19

18

17

16

15

14

13

12

 

 

 

 

 

 

TIL1

TIL0

SCL1

SCL0

SSL1

SSL0

 

 

 

 

 

 

 

 

 

 

 

 

SSI IPL

SCI IPL

TIMER IPL

RESERVED

Reserved, read as zero and should be written with zero for future compatibility.

Figure 3-4 DSP56002 Interrupt Priority Register (IPR)

3.6 DSP56002 PHASE-LOCKED LOOP (PLL) MULTIPLICATION FACTOR

Section 9 of the DSP56000 Family Manual discusses the details of the PLL. The multiplication factor determines the frequency at which the Voltage Controlled Oscillator (VCO) will oscillate. The user sets the multiplication factor by writing to the MF0-MF11 bits in the

PLL control register.

The DSP56002 PLL multiplication factor is set to 1 during hardware reset, which means that the Multiplication Factor Bits MF0-MF11 in the PLL Control Register (PCTL) are set to $000.

MOTOROLA MEMORY MODULES AND OPERATING MODES 3 - 13

For More Information On This Product, Go to: www.freescale.com

Соседние файлы в предмете Радиоприемные устройства