MC9S08EL32 Datasheet, PDF (199/356 Pages) Freescale Semiconductor, Inc – 8-Bit HCS08 Central Processor Unit (CPU)

SLCSV
0x28
0x38
0x3C
Table 12-9. Interrupt Sources Summary (BTM = 1)
I3 I2 I1 I0
1010
1110
1111
Interrupt Source
Byte Framing Error
Reserved
Wakeup
Priority
10
14
15 (Highest)
• No Interrupts Pending
This value indicates that all pending interrupt sources have been serviced. In polling mode, the
SLCSV is read and interrupts serviced until this value reads back 0. This source will not generate
an interrupt of the CPU, regardless of state of SLCIE.
• TX Message Buffer Empty
In byte transfer mode, this interrupt source indicates that the byte in the SLCID has been
transmitted.
• RX Data Buffer Full — No Errors
This interrupt source indicates that a byte has been received and is waiting in SLCID. To clear this
source, SLCID must be read first.
• Bit Error
A unit that is sending a bit on the bus also monitors the bus. A BIT_ERROR must be detected at
that bit time, when the bit value that is monitored is different from the bit value that is sent. The
SLIC will terminate the data transmission upon detection of a bit error, according to the LIN
specification. Bit errors are not checked when the LIN bus is running at high speed due to the
effects of physical layer round trip delay. Bit errors are checked only when BEDD = 0.
• Receiver Buffer Overrun Error
This error is an indication that the receive buffer has not been emptied and additional byte(s) have
been received, resulting in lost data. Because this interrupt is higher priority than the receive buffer
full interrupts, it will appear first when an overflow condition occurs. There will, however, be a
pending receive interrupt which must also be cleared after the buffer overrun flag is cleared. Buffer
overrun errors can be avoided if on reception of data (SLCSV=$14) SLCD0 is read or received data
causes a framing error to occur.
• Byte Framing Error
This error comes from the standard UART definition for byte encoding and occurs when STOP is
sampled and reads back as a 0. STOP should always read as 1. A byte framing error could be
encountered if the bit timing value programmed in BTH:L does not match the bit rate of the
incoming data.
•
• Wakeup
The wakeup interrupt source indicates that the SLIC module has entered SLIC run mode from
SLIC wait mode.
MC9S08EL32 Series and MC9S08SL16 Series Data Sheet, Rev. 3
Freescale Semiconductor
201