VNC2 参数 Datasheet PDF下载

Document No.: FT_000138

VINCULUM-II EMBEDDED DUAL USB HOST CONTROLLER IC Datasheet

Version -

1.0

Clearance No.: FTDI#

143

Time

t10

t11

t12

t13

t14

Description

CLKOUT TO TXE#

Write DATA setup time

Write DATA hold time

WR# setup time

WR# hold time

Minimum

Typical

Maximum

Unit

ns

ns

ns

ns

ns

1

12

0

12

0

7.83

Table 30 S

ynchronous

FIFO mode Read / Write Timing

6.8 General Purpose Timers

In VNC2 there are 4 General Purpose Timers available. Three are available to the designer and one is

reserved for the RTOS.

The timers have the following features:

16 bit

Count down

One shot and auto-reload

enable

Interrupt on zero

6.9 Pulse Width Modulation

VNC2 provides 8 Pulse Width Modulation (PWM) outputs. These can be used to generate PWM signals

which can be used to control motors, DC/DC converters, AC/DC supplies, etc.

The features of the PWM module are as follows:

-

-

-

-

-

-

8 PWM outputs

A trigger input

8-bit prescaler

16-bit counter

Generation of up to 4-pulse signal with controlled output enable and configurable initial state

Interrupt

A single PWM cycle can have up to 4 pulses (8 edges). The PWM block uses a 16-bit counter to

determine the period of a single PWM cycle. This counter counts system clocks which can also be divided

by an optional 8-bit prescaler. The PWM drivers allow the user to select when PWM output toggles. These

values correspond to the values of 16-bit counter. For example, on the timing diagram below -

the 16-bit counter counts to 23 and pwm_out[0] output toggles when the counter‟s current value

is equal to 7, 8, 12, 14, 15, 16, 19 and 22.

Figure 6-24 PWM – Timing Diagram

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