![Texas Instruments AM1802 Скачать руководство пользователя страница 68](http://html.mh-extra.com/html/texas-instruments/am1802/am1802_reference-manual_1094556068.webp)
PLL0_SYSCLK2
PLL1_SYSCLK2
0
1
McASP0
CFGCHIP3[ASYNC3_CLKSRC]
Module
Clock
LPSC
PLL0_AUXCLK
TX/RX
Reference
Clock
Clock
Generator
ACLKX
AHCLKX
AHCLKR
ACLKR
On Chip
Frame Sync
Generator
AFSX
AFSR
Peripheral Clocking
Table 6-7. EMAC Reference Clock Frequencies
POSTDIV
PLLDIV7
OSCIN
PLL Multiplier
Multiplier
Post Divider
Output
Register
Frequency
Register Setting
Frequency
Mode
(1)
Frequency
Setting
PLL0_SYSCLK7
25
24
600 MHz
Div2
300 MHz
5
50 MHz
Div3
200 MHz
3
50 MHz
Div4
150 MHz
2
50 MHz
25
18
450 MHz
Div2
225 MHz
Not Applicable
(2)
Div3
150 MHz
2
50 MHz
Div4
112.5 MHz
Not Applicable
(2)
(1)
See
for explanation of POSTDIV divider modes.
(2)
Certain PLL configurations do not support a 50 MHz clock on PLL0_SYSCLK7.
6.3.5 McASP Clocking
As shown in
, the McASP peripheral requires multiple clock sources. Internally, the module
clock is selected to be either PLL0_SYSCLK2 or PLL1_SYSCLK2 by configuring the ASYNC3_CLKSRC
bit in the chip configuration 3 register (CFGCHIP3) of the System Configuration Module.
The transmit and receive clocks are sourced internally or externally by configuring the McASP clock
control registers ACLKRCTL, AHCLKRCTL, ACLKXCTL, and AHCLKXCTL. If an external clock is driven
into a high-frequency master clock (AHCLKX or AHCLKR), the McASP module allows for a mixed clock
mode where the associated lower frequency clock (ACLKX or ACLKR) can be derived from the
high-frequency master clock through a programmable divider.
When the internal clock source option is selected, the transmit and receive clocks are derived from the
PLL0_AUXCLK clock through programmable dividers.
Figure 6-6. McASP Clocking Diagram
68
Device Clocking
SPRUGX5A
–
May 2011
Copyright
©
2011, Texas Instruments Incorporated
Содержание AM1802
Страница 1: ...AM1802 ARM Microprocessor System Reference Guide Literature Number SPRUGX5A May 2011 ...
Страница 2: ...2 SPRUGX5A May 2011 Submit Documentation Feedback Copyright 2011 Texas Instruments Incorporated ...
Страница 30: ...30 ARM Subsystem SPRUGX5A May 2011 Submit Documentation Feedback Copyright 2011 Texas Instruments Incorporated ...
Страница 144: ...144 Power Management SPRUGX5A May 2011 Submit Documentation Feedback Copyright 2011 Texas Instruments Incorporated ...