Programming Model
MOTOROLA
Multimedia Card/Secure Digital Host Controller Module (MMC/SD)
20-19
20.6.3 MMC/SD Clock Rate Register
The MMC/SD Clock Rate Register defines the clock divider values for CLK_20M and CLK_DIV. These
two signals are used to clock the MMC/SD module. See Section 20.5.4, “System Clock Controller,” for
more information on clock schemes.
NOTE:
The user can write to the MMC/SD Clock Rate Register only when the bus
clock is stopped. Check the CARD_BUS_CLK_RUN bit of the STATUS
register to determine the state of the bus clock.
CLK_RATE
MMC/SD Clock Rate Register
Addr
0x00214008
BIT
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
TYPE
r
r
r
r
r
r
r
r
r
r
r
r
r
r
r
r
RESET
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0x0000
BIT
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
PRESCALER
CLK RATE
TYPE
r
r
r
r
r
r
r
r
r
r
rw
rw
rw
rw
rw
rw
RESET
0
0
0
0
0
0
0
0
0
0
1
1
0
1
1
0
0x0036
Table 20-7. MMC/SD Clock Rate Register Description
Name
Description
Settings
Reserved
Bits 31–6
Reserved—These bits are reserved and should read 0.
PRESCALER
Bits 5–3
Prescaler Divider
—Specifies the divider value to generate
CLK_20M. PERCLK2 feeds into the MMC/SD module from
the clock controller.
000 = CLK_20M is PERCLK2
001 = CLK_20M is PERCLK2 ÷ 2
010 = CLK_20M is PERCLK2 ÷ 3
011 = CLK_20M is PERCLK2 ÷ 3
100 = CLK_20M is PERCLK2 ÷ 4
101 = CLK_20M is PERCLK2 ÷ 5
110 = CLK_20M is PERCLK2 ÷ 5
111 = CLK_20M is PERCLK2 ÷ 5
CLK RATE
Bits 2–0
Inner Bus Clock Divider
—Specifies the divider value to
generate CLK_DIV. The CLK_20M signal feeds into the
inner bus clock divider from the prescaler.
000 = CLK_DIV is CLK_20M
001 = CLK_DIV is CLK_20M ÷ 2
010 = CLK_DIV is CLK_20M ÷ 4
011 = CLK_DIV is CLK_20M ÷ 8
100 = CLK_DIV is CLK_20M ÷ 16
101 = CLK_DIV is CLK_20M ÷ 32
110 = CLK_DIV is CLK_20M ÷ 64
111 = CLK_DIV is CLK_20M ÷ 64
Summary of Contents for DragonBall MC9328MX1
Page 68: ...1 12 MC9328MX1 Reference Manual MOTOROLA Introduction ...
Page 86: ...2 18 MC9328MX1 Reference Manual MOTOROLA Signal Descriptions and Pin Assignments ...
Page 116: ...3 30 MC9328MX1 Reference Manual MOTOROLA Memory Map ...
Page 126: ...4 10 MC9328MX1 Reference Manual MOTOROLA ARM920T Processor ...
Page 160: ...8 8 MC9328MX1 Reference Manual MOTOROLA System Control ...
Page 272: ...13 32 MC9328MX1 Reference Manual MOTOROLA DMA Controller ...
Page 281: ...Programming Model MOTOROLA Watchdog Timer Module 14 9 ...
Page 282: ...14 10 MC9328MX1 Reference Manual MOTOROLA Watchdog Timer Module ...
Page 300: ...15 18 MC9328MX1 Reference Manual MOTOROLA Analog Signal Processor ASP ...
Page 438: ...18 16 MC9328MX1 Reference Manual MOTOROLA Serial Peripheral Interface Modules SPI 1 and SPI 2 ...
Page 478: ...19 40 MC9328MX1 Reference Manual MOTOROLA LCD Controller ...
Page 574: ...21 32 MC9328MX1 Reference Manual MOTOROLA Memory Stick Host Controller MSHC Module ...
Page 598: ...23 16 MC9328MX1 Reference Manual MOTOROLA Real Time Clock RTC ...
Page 670: ...24 72 MC9328MX1 Reference Manual MOTOROLA SDRAM Memory Controller ...
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Page 736: ...26 10 MC9328MX1 Reference Manual MOTOROLA General Purpose Timers ...
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Page 900: ...30 46 MC9328MX1 Reference Manual MOTOROLA Synchronous Serial Interface SSI ...
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