Datasheet

I/O Registers
MC68HC908GR60A • MC68HC908GR48A • MC68HC908GR32A Data Sheet, Rev. 5
Freescale Semiconductor 167
WAKE — Wakeup Condition Bit
This read/write bit determines which condition wakes up the ESCI: a 1 (address mark) in the MSB
position of a received character or an idle condition on the RxD pin. Reset clears the WAKE bit.
1 = Address mark wakeup
0 = Idle line wakeup
ILTY — Idle Line Type Bit
This read/write bit determines when the ESCI starts counting 1s as idle character bits. The counting
begins either after the start bit or after the stop bit. If the count begins after the start bit, then a string
of 1s preceding the stop bit may cause false recognition of an idle character. Beginning the count after
the stop bit avoids false idle character recognition, but requires properly synchronized transmissions.
Reset clears the ILTY bit.
1 = Idle character bit count begins after stop bit
0 = Idle character bit count begins after start bit
PEN — Parity Enable Bit
This read/write bit enables the ESCI parity function (see Table 13-5). When enabled, the parity
function inserts a parity bit in the MSB position (see Table 13-3). Reset clears the PEN bit.
1 = Parity function enabled
0 = Parity function disabled
PTY — Parity Bit
This read/write bit determines whether the ESCI generates and checks for odd parity or even parity
(see Table 13-5). Reset clears the PTY bit.
1 = Odd parity
0 = Even parity
NOTE
Changing the PTY bit in the middle of a transmission or reception can
generate a parity error.
13.8.2 ESCI Control Register 2
ESCI control register 2 (SCC2):
• Enables these CPU interrupt requests:
– SCTE bit to generate transmitter CPU interrupt requests
– TC bit to generate transmitter CPU interrupt requests
– SCRF bit to generate receiver CPU interrupt requests
– IDLE bit to generate receiver CPU interrupt requests
Table 13-5. Character Format Selection
Control Bits Character Format
M PEN:PTY Start Bits Data Bits Parity Stop Bits Character Length
0 0 X 1 8 None 1 10 bits
1 0 X 1 9 None 1 11 bits
0 1 0 1 7 Even 1 10 bits
0 1 1 1 7 Odd 1 10 bits
1 1 0 1 8 Even 1 11 bits
1 1 1 1 8 Odd 1 11 bits
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