MOTOROLA
Chapter 9. Clock Module
9-9
Memory Map and Registers
Table 9-5. SYNSR Field Descriptions
Bit(s)
Name
Description
7
PLLMODE
Clock mode bit. The PLLMODE bit is configured at reset and reflects the clock mode
as shown in Table 9-6.
1 PLL clock mode
0 External clock mode
6
PLLSEL
PLL select. Configured at reset and reflects the PLL mode as shown in Table 9-6.
1 Normal PLL mode
0 1:1 PLL mode
5
PLLREF
PLL reference. Configured at reset and reflects the PLL reference source in normal
PLL mode as shown in Table 9-6.
1 Crystal clock reference
0 External clock reference
4
LOCKS
Sticky indication of PLL lock status.
1 No unintentional PLL loss of lock since last system reset or MFD change
0 PLL loss of lock since last system reset or MFD change or currently not locked due
to exit from STOP with FWKUP set
The lock detect function sets the LOCKS bit when the PLL achieves lock after:
• A system reset
• A write to SYNCR that changes the MFD[2:0] bits
When the PLL loses lock, LOCKS is cleared. When the PLL relocks, LOCKS remains
cleared until one of the two listed events occurs.
In stop mode, if the PLL is intentionally disabled, then the LOCKS bit reflects the value
prior to entering stop mode. However, if FWKUP is set, then LOCKS is cleared until
the PLL regains lock. Once lock is regained, the LOCKS bit reflects the value prior to
entering stop mode. Furthermore, reading the LOCKS bit at the same time that the PLL
loses lock does not return the current loss of lock condition.
In external clock mode, LOCKS remains cleared after reset. In normal PLL mode and
1:1 PLL mode, LOCKS is set after reset.
3
LOCK
Set when the PLL is locked. PLL lock occurs when the synthesized frequency is within
approximately 0.75 percent of the programmed frequency. The PLL loses lock when a
frequency deviation of greater than approximately 1.5 percent occurs. Reading the
LOCK flag at the same time that the PLL loses lock or acquires lock does not return
the current condition of the PLL. The power-on reset circuit uses the LOCK bit as a
condition for releasing reset.
If operating in external clock mode, LOCK remains cleared after reset.
1 PLL locked
0 PLL not locked
Summary of Contents for ColdFire MCF5281
Page 124: ...3 20 MCF5282 User s Manual MOTOROLA EMAC Instruction Set Summary ...
Page 141: ...MOTOROLA Chapter 5 Static RAM SRAM 5 5 SRAM Programming Model ...
Page 142: ...5 6 MCF5282 User s Manual MOTOROLA SRAM Programming Model ...
Page 168: ...6 26 MCF5282 User s Manual MOTOROLA Interrupts ...
Page 186: ...7 18 MCF5282 User s Manual MOTOROLA Functional Description ...
Page 228: ...9 22 MCF5282 User s Manual MOTOROLA Functional Description ...
Page 246: ...10 18 MCF5282 User s Manual MOTOROLA Low Power Wakeup Operation ...
Page 254: ...11 8 MCF5282 User s Manual MOTOROLA Memory Map and Registers ...
Page 264: ...12 10 MCF5282 User s Manual MOTOROLA Chip Select Registers ...
Page 280: ...13 16 MCF5282 User s Manual MOTOROLA Misaligned Operands ...
Page 314: ...14 34 MCF5282 User s Manual MOTOROLA MCF5282 External Signals ...
Page 339: ...MOTOROLA Chapter 15 Synchronous DRAM Controller Module 15 25 SDRAM Example ...
Page 340: ...15 26 MCF5282 User s Manual MOTOROLA SDRAM Example ...
Page 356: ...16 16 MCF5282 User s Manual MOTOROLA DMA Controller Module Functional Description ...
Page 408: ...17 52 MCF5282 User s Manual MOTOROLA Buffer Descriptors ...
Page 446: ...20 24 MCF5282 User s Manual MOTOROLA Interrupts ...
Page 474: ...22 18 MCF5282 User s Manual MOTOROLA Programming Model ...
Page 510: ...23 36 MCF5282 User s Manual MOTOROLA Operation ...
Page 526: ...24 16 MCF5282 User s Manual MOTOROLA I2C Programming Examples ...
Page 672: ...28 12 MCF5282 User s Manual MOTOROLA Functional Description ...
Page 718: ...29 46 MCF5282 User s Manual MOTOROLA Motorola Recommended BDM Pinout ...
Page 750: ...32 8 MCF5282 User s Manual MOTOROLA Ordering Information ...