MSC8122 View Datasheet(PDF) - Freescale Semiconductor

Part Name

Description

Manufacturer

MSC8122

Quad Digital Signal Processor

Freescale Semiconductor 

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

• 300 MHz core

• 400 MHz core

• 500 MHz core

CLKOUT frequency jitter1

—

CLKOUT phase jitter1 with CLKIN phase jitter of ±100 ps.

—

Notes: 1. Peak-to-peak.

2. Not tested. Guaranteed by design.

Electrical Characteristics

Max

0.3

see Table 8

3

150

—

100

1200

1600

2000

200

500

Unit

ns

MHz

ns

ps

KHz

MHz

MHz

MHz

MHz

MHz

ps

ps

2.5.4 Reset Timing

The MSC8122 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 MSC8122 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.

Name

Power-on reset

(PORESET)

External hard

reset (HRESET)

External soft reset

(SRESET)

Software

watchdog reset

Bus monitor reset

Host reset

command through

the TAP

Direction

Input

Input/ Output

Input/ Output

Internal

Internal

Internal

Table 10. Reset Sources

Description

Initiates the power-on reset flow that resets the MSC8122 and configures various attributes of the

MSC8122. On PORESET, the entire MSC8122 device is reset. SPLL states is reset, HRESET and

SRESET are driven, the SC140 extended cores are reset, and system configuration is sampled. The

clock mode (MODCK bits), reset configuration mode, boot mode, Chip ID, and use of either a DSI 64

bits port or a System Bus 64 bits port are configured only when PORESET is asserted.

Initiates the hard reset flow that configures various attributes of the MSC8122. While HRESET is

asserted, SRESET is also asserted. HRESET is an open-drain pin. Upon hard reset, HRESET and

SRESET are driven, the SC140 extended cores are reset, and system configuration is sampled. The

most configurable features are reconfigured. These features are defined in the 32-bit hard reset

configuration word described in Hard Reset Configuration Word section of the Reset chapter in the

MSC8122 Reference Manual.

Initiates the soft reset flow. The MSC8122 detects an external assertion of SRESET only if it occurs

while the MSC8122 is not asserting reset. SRESET is an open-drain pin. Upon soft reset, SRESET is

driven, the SC140 extended cores are reset, and system configuration is maintained.

When the MSC8122 watchdog count reaches zero, a software watchdog reset is signalled. The

enabled software watchdog event then generates an internal hard reset sequence.

When the MSC8122 bus monitor count reaches zero, a bus monitor hard reset is asserted. The

enabled bus monitor event then generates an internal hard reset sequence.

When a host reset command is written through the Test Access Port (TAP), the TAP logic asserts the

soft reset signal and an internal soft reset sequence is generated.

MSC8122 Quad Digital Signal Processor Data Sheet, Rev. 15

Freescale Semiconductor

19

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