mfr4300 Freescale Semiconductor, Inc, mfr4300 Datasheet - Page 52

• Manufacturer Part Number: mfr4300
• Description: Flexray Communication Controllers
• Manufacturer: Freescale Semiconductor, Inc

Device Overview
Figure 2-9
Figure 2-10
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The CC’s HCS12 interface supports the paged and the unpaged modes of the HCS12 External Bus
Interface connected to it.
The FlexRay HCS12 interface is implemented as an synchronous HCS12 External Bus slave
module, thus enabling the fast data exchange between them.
The FlexRay CC MCU interface decodes the addresses of read/write transactions to its internal
registers, and generates its internal chip select signal, CS, using the address/data lines PA[0:7],
PB[0:7], ACS[0:2], and XADDR[14:19]:
— The address and data lines PA[0:7], PB[0:7] are multiplexed. They are denoted ADR[0:15]
The HCS12 interface accepts only aligned 16-bit read and 8-bit or 16-bit write transactions. The
HCS12 interface does not support 8-bit read accesses.
— The internal chip select, CS, the low byte strobe, LSTRB, the least significant bit of the address,
RW_CC# indicates the direction of data transfer for a transaction.
INT_CC# is an interrupt line that can be used for requesting, by means of the internal interrupt
controller, a service routine from the HCS12 device.
shows how to connect the FlexRay CC to an HCS12 MCU with EBI paged mode support.
when referring to the address, and DATA[0:15] when referring to the data. The FlexRay CC is
selected only when the address ADR[13:15] matches ACS[0:2] (ADR13 matches ACS0,
ADR12 matches ACS1, etc.) and the address XADDR[14:19] matches 0.
ADR0, and the read/write select, RW, are used to determine the type of access, as shown in
Table
shows how to connect he FlexRay CC to an HCS12 MCU with EBI unpaged mode support.
2-9.
1
2
3
Write data from PA to even byte address and from PB to odd byte address.
Write data from PB.
Read data from even byte address at PA and from odd byte address at PB.
CS
0
1
1
1
1
1
1
1
1
RW
X
0
0
0
0
1
1
1
1
Table 2-9. HCS12 Access Types
LSTRB
X
0
0
1
1
0
0
1
1
MFR4300 Data Sheet, Rev. 3
ADR0
X
0
1
0
1
0
1
0
1
No access
16-bit write to word address
8-bit write to an odd address
8-bit write to an even address
Not supported
16-bit read from an even address
Not supported
Not supported
Not supported
Type of Access
1
2
2
3
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