TUSB3200CPAH datasheet(32/93 Pages) TI

32 / 93 page

2–16

The corresponding values to program into the ACGFRQ registers are:

ACGFRQ2 = 01100001b = 61h

ACGFRQ1 = 10101000b = A8h

ACGFRQ0 = 00000000b = 00h

Keep in mind that writing to the ACGFRQ0 register loads the frequency synthesizer with the new 24-bit value.

Example Frequency Resolution Calculation

To illustrate the frequency resolution capabilities of the ACG, the next possible higher and lower frequencies for

MCLKO can be calculated.

To get the next possible higher frequency of MCLKO equal to 24.57600384 MHz, increase the value of N by 1 LSB.

Thus, N = 011000.011010100000000001 binary.

To get the next possible lower frequency of MCLKO equal to 24.57599600 MHz, decrease the value of N by 1 LSB.

Thus, N = 011000.011010011111111111 binary.

For this example with a nominal MCLKO frequency of 24.576 MHz, the frequency resolution is approximately 4 Hz.

2.2.8.2 Capture Counter and Register

The capture counter and register circuit consists of a 16-bit free running counter which runs at the capture clock

frequency. The capture clock source can be selected by using the MCLKCP bit in the ACGCTL register to select either

the MCLKO or MCLKO2 signal. With each USB start-of-frame (SOF) signal or pseudo-start-of-frame (PSOF) signal,

the capture counter value is stored into the 16-bit capture register. This value is valid until the next SOF or PSOF signal

occurs (~1 ms). The MCU can read the 16-bit capture register value by reading the ACGCAPH and ACGCAPL

registers.

2.2.9

Microcontroller Unit

The 8052 core used in the TUSB3200 is based on the industry standard 8052 MCU and is software compatible with

the 8052, 8032, 80C52, 80C53, and 87C52 MCUs. Therefore, refer to a standard 8052 data manual for more details

if needed.

2.2.10 External MCU Mode Operation

The external MCU mode of operation is provided for firmware development using an in-circuit emulator (ICE). In the

external MCU mode, the internal 8052 MCU core of the TUSB3200 is disabled. Also in the external MCU mode, the

GPIO ports are used for the external MCU data, address, and control signals. Refer to section 1.7,

Terminal Functions

– External MCU Mode, for details. In this mode, the external MCU or ICE is able to access the memory mapped IO

registers, the USB configuration blocks and the USB buffer space. Refer to section 1.8, Device Operation Modes,

for information regarding the various modes of operation.

Texas Instruments has developed the TUSB3200 evaluation module (EVM) to allow customers to develop application

firmware and to evaluate device performance. The EVM board provides a 40-pin dip socket for an ICE in addition

to headers to allow expansion of the system in a variety of ways.

2.2.11 Interrupt Logic

The 8052 MCU core used in the TUSB3200 supports all the standard interrupt sources. The five standard MCU

interrupt sources are timer 0, timer 1, serial port, external 1 (INT1), and external 0 (INT0).

All of the additional interrupt sources within the TUSB3200 device are ORed together to generate the INT0 signal

to the MCU. Refer to the interrupt vector register for more details on the other TUSB3200 interrupt sources.

TUSB3200CPAH 数据表(PDF) 32 Page - Texas Instruments

TUSB3200CPAH 数据表(HTML) 32 Page - Texas Instruments

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93

数据表下载