2 cfm clock divider register (cfmclkd), 2 cfm clock divider register (cfmclkd) -9 – Motorola ColdFire MCF5281 User Manual
Page 121
ColdFire Flash Module (CFM)
Freescale Semiconductor
6-9
6.3.4.2
CFM Clock Divider Register (CFMCLKD)
The CFMCLKD is used to set the frequency of the clock used for timed events in program and erase
algorithms.
All bits in CFMCLKD are readable. Bit 7 is a read-only status bit, while bits 6–0 can only be written once.
7
CBEIE
Command buffer empty interrupt enable. The CBEIE bit is readable and writable.
CBEIE enables an interrupt request when the command buffer for the Flash
physical blocks is empty.
1 Request an interrupt whenever the CBEIF flag is set.
0 Command buffer empty interrupts disabled
6
CCIE
Command complete interrupt enable. The CCIE bit is readable and writable.
CCIE enables an interrupt when the command executing for the Flash is
complete.
1 Request an interrupt whenever the CCIF flag is set.
0 Command complete interrupts disabled
5
KEYACC
Enable security key writing. The KEYACC bit is readable and only writable if the
KEYEN bit in the CFMSEC register is set.
1 Writes to the Flash array are interpreted as keys to open the back door.
0 Writes to the Flash array are interpreted as the start of a program, erase, or
verify sequence.
4–0
—
Reserved, should be cleared.
7
6
5
0
Field
DIVLD
PRDIV8
DIV
Reset
0000_0000
R/W
R
R/W
Address
IPSBAR + 0x1D_0002
Figure 6-5. CFM Clock Divider Register (CFMCLKD)
Table 6-5. CFMCLKD Field Descriptions
Bits
Name
Description
7
DIVLD
Clock divider loaded
1 CFMCLKD has been written since the last reset.
0 CFMCLKD has not been written.
6
PRDIV8
Enable prescaler divide by 8
1 Enables a prescaler that divides the CFM clock by 8 before it enters the
CFMCLKD divider.
0 The CFM clock is fed directly into the CFMCLKD divider.
5–0
DIV
Clock divider field. The combination of PRDIV8 and DIV[5:0] effectively divides the
CFM input clock down to a frequency between 150 kHz and 200 kHz. The
frequency range of the CFM clock is 150 kHz to 102.4 MHz.
Table 6-4. CFMCR Field Descriptions
Bits
Name
Description
MCF5282 and MCF5216 ColdFire Microcontroller User’s Manual, Rev. 3