MSC8101ADS Freescale Semiconductor / Motorola, MSC8101ADS Datasheet - Page 12

• Manufacturer Part Number: MSC8101ADS
• Description: MSC8101 APP DEV SYSTEM
• Manufacturer: Freescale Semiconductor / Motorola

Signals/Connections
1-8
BR
BG
ABB
IRQ2
TS
AACK
ARTRY
DBG
DBB
IRQ3
D[0–31]
Signal
Input/Output
Output
Input
Input/Output
Output
Input
Input/Output
Output
Input
Input
Input/Output
Input/Output
Input
Input/Output
Output
Input
Input/Output
Output
Input
Input
Input/Output
Data Flow
Table 1-5.
Bus Request
An output when an external arbiter is used. The MSC8101 asserts this pin to request ownership of
the bus.
An input when an internal arbiter is used. An external master should assert this pin to request bus
ownership from the internal arbiter.
Bus Grant
An output when an internal arbiter is used. The MSC8101 asserts this pin to grant bus ownership to
an external bus master.
An input when an external arbiter is used. The external arbiter should assert this pin to grant bus
ownership to the MSC8101.
Address Bus Busy
The MSC8101 asserts this pin for the duration of the address bus tenure. Following an address
acknowledge (AACK) signal, which terminates the address bus tenure, the MSC8101 deasserts
ABB for a fraction of a bus cycle and then stops driving this pin.
The MSC8101 does not assume bus ownership while it this pin is asserted by an external bus
master.
Interrupt Request 2
One of the eight external lines that can request a service routine, via the internal interrupt controller,
from the SC140 core.
Bus Transfer Start
Signals the beginning of a new address bus tenure. The MSC8101 asserts this signal when one of
its internal bus masters (SC140 core or DMA controller) begins an address tenure. When the
MSC8101 senses this pin being asserted by an external bus master, it responds to the address bus
tenure as required (snoop if enabled, access internal MSC8101 resources, memory controller
support).
Address Acknowledge
A bus slave asserts this signal to indicate that it identified the address tenure. Assertion of this signal
terminates the address tenure.
Address Retry
Assertion of this signal indicates that the bus transaction should be retried by the bus master. The
MSC8101 asserts this signal to enforce data coherency with its internal cache and to prevent
deadlock situations.
Data Bus Grant
An output when an internal arbiter is used. The MSC8101 asserts this pin as an output to grant data
bus ownership to an external bus master.
An input when an external arbiter is used. The external arbiter should assert this pin as an input to
grant data bus ownership to the MSC8101.
Data Bus Busy
The MSC8101 asserts this pin as an output for the duration of the data bus tenure. Following a TA,
which terminates the data bus tenure, the MSC8101 deasserts DBB for a fraction of a bus cycle and
then stops driving this pin.
The MSC8101 does not assume data bus ownership while DBB is asserted by an external bus
master.
Interrupt Request 3
One of the eight external lines that can request a service routine, via the internal interrupt controller,
from the SC140 core.
Data Bus Most Significant Word
In write transactions the bus master drives the valid data on this bus. In read transactions the slave
drives the valid data on this bus. In Host Port Disabled mode, these 32 bits are part of the 64-bit data
bus. In Host Port Enabled mode, these bits are used as the bus in 32-bit mode.
System Bus, HDI16, and Interrupt Signals (Continued)
MSC8101 Technical Data, Rev. 19
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Description
Freescale Semiconductor