TMS320_13 datasheet(35/70 Pages) TI1

35 / 70 page

TMS320C25 50

SPRS010B — MAY 1987 — REVISED NOVEMBER 1990

POST OFFICE BOX 1443

 HOUSTON, TEXAS 77001

CLOCK CHARACTERISTICS AND TIMING

The TMS320C25-50 can use either its internal oscillator or an external frequency source for a clock.

internal clock option

The internal oscillator is enabled by connecting a crystal across X1 and X2, CLKIN. The frequency of CLKOUT1

is one-fourth the crystal fundamental frequency. The crystal should be in either fundamental or overtone mode,

and parallel resonant, with an effective series resistance of 30 , a power dissipation of 1 mW, and be specified

at a load capacitance of 20 pF. Note that overtone crystals require an additional tuned LC circuit.

PARAMETER

TEST CONDITIONS

MIN

TYP†

MAX

UNIT

Input clock frequency

TA =0Cto70C

6.7

51.2

MHz

fsx

Serial port frequency

TA =0Cto70C

6.4

MHz

C1, C2

TA =0Cto70C

† The serial port was tested at a minimum frequency of 1.25 MHz. However, the serial port was fully static but will properly function down to

fsx =0Hz.

X2/CLKIN

Crystal

Figure 6. Internal Clock Option

external clock option

An external frequency source can be used by injecting the frequency directly into X2/CLK, with X1 left

unconnected. The external frequency injected must conform to specifications listed in the following table.

switching characteristics over recommended operating conditions (see Note 3)

MIN

NOM

MAX

UNIT

tc(C)

CLKOUT1, CLKOUT2 cycle time

78.13

597

td(CIH-C)

CLKIN high to CLKOUT1, CLKOUT2, STRB high, low

tf(C)

CLKOUT1, CLKOUT2, STRB fall time

tr(C)

CLKOUT1, CLKOUT2, STRB rise time

tw(CL)

CLKOUT1, CLKOUT2, STRB low pulse duration

2Q -- 7

2Q + 3

tw(CH)

CLKOUT1, CLKOUT2, STRB high pulse duration

2Q -- 3

2Q + 7

td(C1-C2)

CLKOUT1hightoCLKOUT2 low,

CLKOUT2 high to CLKOUT1 high, etc.

Q-- 6

Q+ 2

NOTE 3: Q = 1/4 tc(C)

TMS320 датащи(PDF) 35 Page - Texas Instruments

TMS320 датащи(HTML) 35 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

датащи скачать

ссылки URL