MSC8112 Datasheet, PDF (18/44 Pages) Freescale Semiconductor, Inc – Dual Core Digital Signal Processor

Electrical Characteristics
2.5.3 Clock and Timing Signals
The following sections include a description of clock signal characteristics. Table 7 shows the maximum frequency values for
internal (Core, Reference, Bus, and DSI) and external (CLKIN and CLKOUT) clocks. The user must ensure that maximum
frequency values are not exceeded.
Table 7. Maximum Frequencies
Characteristic
Core frequency
Reference frequency (REFCLK)
Internal bus frequency (BLCK)
DSI clock frequency (HCLKIN)
External clock frequency (CLKIN or CLKOUT)
Maximum in MHz
300
100
100
HCLKIN ≤ (min{70 MHz, CLKOUT})
100
Table 8. Clock Frequencies
Characteristics
CLKIN frequency
BCLK frequency
Reference clock (REFCLK) frequency
Output clock (CLKOUT) frequency
SC140 core clock frequency
Note: The rise and fall time of external clocks should be 3 ns maximum
Symbol
F_CLKIN
F_BCLK
F_REFCLK
F_CLKOUT
F_CORE
Table 9. System Clock Parameters
Characteristic
Min
Phase jitter between BCLK and CLKIN
—
CLKIN frequency
20
CLKIN slope
—
CLKIN period jitter¹
—
CLKIN jitter spectrum
150
PLL input clock (after predivider)
20
PLL output frequency (VCO output)
800
CLKOUT frequency jitter¹
—
CLKOUT phase jitter¹ with CLKIN phase jitter of ±100 ps.
—
Notes: 1. Peak-to-peak.
2. Not tested. Guaranteed by design.
Min
20
40
40
40
200
Max
0.3
see Table 8
3
150
—
100
1200
200
500
Max
100
100
100
100
300
Unit
ns
MHz
ns
ps
KHz
MHz
MHz
ps
ps
2.5.4 Reset Timing
The MSC8112 has several inputs to the reset logic:
• Power-on reset (PORESET)
• External hard reset (HRESET)
• External soft reset (SRESET)
• Software watchdog reset
• Bus monitor reset
• Host reset command through JTAG
All MSC8112 reset sources are fed into the reset controller, which takes different actions depending on the source of the reset.
The reset status register indicates the most recent sources to cause a reset. Table 10 describes the reset sources.
MSC8112 Dual Core Digital Signal Processor Data Sheet, Rev. 0
18
Freescale Semiconductor