BCM2835 Просмотр технического описания (PDF) - Broadcom Corporation
Номер в каталоге
Компоненты Описание
производитель
BCM2835 Datasheet PDF : 205 Pages
| |||
Offset
Address
0x080 USB_MDIO_CNTL
0x084 USB_MDIO_GEN
0x088 USB_VBUS_DRV
Description
MDIO interface control
Data for MDIO interface
Vbus and other Miscellaneous controls
Size
Read/
Write
R/W
32 R/W
R/W
USB MDIO Control (USB_MDIO_CNTL)
Address
0x 7E98 0080
Bit
Number
31
30-24
23
22
21
20
19:16
15:0
Field
Name
mdio_busy
-
bb_mdo
bb_mdc
bb_enbl
freerun
mdc_ratio
mdi
Description
Read/
Write
Reset
1= MDIO read or write in progress
0= MDIO Idle
R
0
Unused
-
0
Direct write (bitbash) MDO output
R/W
0
Direct write (bitbash) MDC output
R/W
0
1= MDIO bitbash enable
0= MDIO under control of the phy
R/W
0
1= MDC is continous active
0 = MDC only active during data transfer
R/W
0
MDC clock freq is sysclk/mdc_ratio
R/W
0
16-bit read of MDIO input shift register. Updates on RO
0
falling edge of MDC
Table 15-1 MDIO Control
USB MDIO Data (USB_MDIO_DATA)
Address
0x 7E98 0084
Bit
Number
31-0
31-0
Field
Name
mdio_data
mdio_data
Description
32-bit sequence to send over MDIO bus
32-bit sequence received from MDIO bus
Read/
Write
Reset
W
0
R
0
Table 15-2 USB MDIO data
A Preamble is not auto-generated so any MDIO access must be preceded by a write to this
register of 0xFFFFFFFF. Furthermore, a bug in the USB PHY requires an extra clock edge so
a write of 0x00000000 must follow the actual access.
06 February 2012 Broadcom Europe Ltd. 406 Science Park Milton Road Cambridge CB4 0WW
© 2012 Broadcom Corporation. All rights reserved
Page 203
Share Link: 