ACK! dAck! 2.0 Manuel d'utilisateur télécharger pdf (Page 54)

Philips Semiconductors

ISP1581

USB 2.0 HS interface device

Objective speciﬁcation Rev. 02 — 23 October 2000 54 of 73

9397 750 07648

12.4 DMA timing

12.4.1 PIO mode

General

cy(RW)

read/write cycle time 60 - ns

AVLL

address set-up time before ALE LOW 3 - ns

I1VLL

R/W set-up time before ALE LOW 3 - ns

LLI2L

ALE LOW to DS LOW delay 5 - ns

I2HI1X

R/W hold time after DS HIGH 5 - ns

Table 83: Parallel I/O timing parameters: multiplexed address/data bus

…continued

Symbol Parameter Min Max Unit

(1) The device address consists of signals CS1, CS0, DA2, DA1 and DA0.

(2) The data bus width depends on the PIO access command used. Task File register access uses 8 bits (DATA[7:0]), except

for Task File register 1F0 which uses 16 bits (DATA[15:0]). DMA commands 04H and 05H also use a 16-bit data bus.

(3) The device can negate IORDY to extend the PIO cycle with wait states. The host determines whether or not to extend the

current cycle after t

su4

following the assertion of DIOR or DIOW. The following three cases are distinguished:

a) Device keeps IORDY released (high-impedance): no wait state is generated.

b) Device negates IORDY during t

su4

, but re-asserts IORDY before t

su4

expires: no wait state is generated.

c) Device negates IORDY during t

su4

and keeps IORDY negated for at least 5 ns after t

su4

expires: a wait state is

generated. The cycle is completed as soon as IORDY is re-asserted. For extended read cycles (DIOR asserted), the

read data on lines DATAn must be valid at t

before IORDY is asserted.

(4) DIOR and DIOW have a programmable polarity: shown here as active LOW signals.

Fig 13. PIO mode timing.

HIGH

(write) DATA

[

7:0

]

(2)

(read) DATA

[

7:0

]

(2)

device

(1)

address

valid

DIOR, DIOW

(4)

IORDY

(3a)

IORDY

(3b)

IORDY

(3c)

su1

su2

su5

su4

su3

(min)

cy1

MGT499

1 2 ... 49 50 51 52 53 54 55 56 57 58 59 ... 72 73

Commentaires sur ces manuels

Pas de commentaire

ACK! dAck! 2.0 Manuel d'utilisateur Page 54

Commentaires sur ces manuels