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MC68HC11PH8 Datasheet, PDF (122/264 Pages) Motorola, Inc – High-density Complementary Metal Oxide Semiconductor (HCMOS) Microcomputer Unit | |||
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NF2 â Noise error ï¬ag 2
1 (set) â Noise detected.
0 (clear) â No noise detected.
This bit is set when noise is detected on the receive line during an MI BUS pull ï¬eld.
6.6.6 S2SR2 â MI BUS2 status register 2
SCI/MI 2 status 2 (S2SR2)
Address bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
$0055 0
0
0
0
0
0
0 RAF2 0000 0000
RAF2 â Receiver active ï¬ag (read only)
6
1 (set) â A character is being received.
0 (clear) â A character is not being received.
6.6.7 S2DRL â MI BUS2 data register
SCI/MI 2 data low (S2DRL)
Address bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
$0057 R7T7B R6T6B R5T5B R4T4B R3T3B R2T2B R1T1B R0T0B undeÃned
0
1
0
1 S1 S2 S3 1 Pull Ãeld
A2 A1 A0 D4 D3 D2 D1 D0 Push Ãeld
This register forms the 8-bit data/address word for the MI push ï¬eld and contains the 3-bit data
word received as the MI pull ï¬eld.
R/T[7:0] â Receiver/transmitter data bits [7:0]
READ: Reads access the three bits of pull ï¬eld data (stored in bits 3â1) of the read-only MI BUS
receive data register. Bits [7:4, 0] are a ï¬xed data pattern when a valid status and end-of-frame is
returned. A valid status is represented by the following data pattern: 0101 xxx1 (bits 7â0), where
âxxxâ is the status. All ones in the receive data register indicate that an error occurred on the
MI BUS. Bits are received LSB ï¬rst by the MCU, and the status bits map as shown in the above
table.
WRITE: Writes access the eight bits of the write-only MI BUS transmit data register. MI BUS
devices require a 5-bit data pattern followed by a 3-bit address pattern to be sent during the push
ï¬eld. The data pattern is mapped to the lowest ï¬ve bits of the data register and the address to the
highest three bits, as shown in the above table. Thus MI-data[4:0] is written to S2DRL[4:0] and
MI-address[2:0] is written to S2DRL[7:5].
MOTOROLA
6-12
MOTOROLA INTERCONNECT BUS (MI BUS)
TPG
MC68HC11PH8
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