Maxim-integrated MAXQ622 Uživatelský manuál stáhnout pdf (Strana 175)

MAXQ612/MAXQ622 User’s Guide

Maxim Integrated 12-5

Note: Writes to this register are ignored when UBUSY = 1.

12.3.2 USB Data Register (UDATA)

This register is used for supplying data for supported USB register write operation request and for returning data for

USB register read operation.

Bits 7 to 0: USB Data Register (UDATA[7:0]). These data register bits are used for supplying data for supported USB

12.4 USB SIE Internal Register Descriptions

The internal control and data registers are accessed through the UADDR and UDATA registers as previously described.

These internal registers control all aspects of the SIE.

12.4.1 Function Address Register (FNADDR)

Note: Read access only when USBEN = 1. Reading the function address before USBEN = 1 can compromise USB functionality.

Bit 7: Reserved. Reads returns zero.

Bits 6 to 0: USB Register Address (FNADDR[6:0]). These register bits represent a unique value that identifies the

USB function. Upon reset and power-up, the address bits are defaulted to zero and are set by host during the enumera-

tion process. The address zero is reserved as the default value and cannot be assigned to any function. This register

also is cleared to 00h by a USB bus reset. The SIE updates this register after receiving the ACK handshake at the

conclusion of a Set_Address request from the host.

UDATA

USB Data Register

M4[05h]

FNADDR

Function Address Register

UADDR[4:0] = 01h

Bit # 7 6 5 4 3 2 1 0

Name UDATA7 UDATA6 UDATA5 UDATA4 UDATA3 UDATA2 UDATA1 UDATA0

Reset 0 0 0 0 0 0 0 0

Access rw rw rw rw rw rw rw rw

Bit # 7 6 5 4 3 2 1 0

Name — FNADDR6 FNADDR5 FNADDR4 FNADDR3 FNADDR2 FNADDR1 FNADDR0

Reset 0 0 0 0 0 0 0 0

Access r r r r r r r r

1 2 ... 170 171 172 173 174 175 176 177 178 179 180 ... 254 255

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Maxim-integrated MAXQ622 Uživatelský manuál Strana 175