Section 19
Keyboard Buffer Control Unit (PS2)
Rev. 1.00 Apr. 28, 2008 Page 603 of 994
REJ09B0452-0100
Read KBCRL
KBF = 0?
RXCR3 to RXCR0
≥
B'1001?
Disable receive abort
requests
Yes
Start
Receive state
Read KBCRH
Processing 1
KCLKO = 0
(receive abort request)
Retransmit
command transmission
(data)?
KBE = 0
(disable KBBR reception
and clear receive counter)
Set start bit
(KDO = 0)
Clear I/O inhibit
(KCLKO = 1)
Transmit data
To transmit operation
KBE = 0
(disable KBBR reception
and clear receive counter)
KBE = 1
(enable KB operation)
Clear I/O inhibit
(KCLKO = 1)
To receive operation
[1] Read KBCRL, and if KBF = 1,
perform processing 1.
[2] Read KBCRH, and if the value of
bits RXCR3 to RXCR0 is less
than B'1001, write 0 in KCLKO to
abort reception.
[3] If the value of bits RXCR3 to
RXCR0 is B'1001 or greater, wait
until stop bit reception is
completed, then perform receive
data processing, and proceed to
the next operation.
If the value of bits RXCR3 to
RXCR0 is B'1001 or greater, the
parity bit is being received. With
the PS2 interface, a receive abort
request following parity bit
reception is disabled. Wait until
stop bit reception is completed,
perform receive data processing
and clear the KBF flag, then
proceed to the next operation.
Yes
No
No
No
Yes
[1]
[2]
[3]
Figure 19.7 Sample Receive Abort Processing Flowchart (1)
Summary of Contents for H8S/2100 Series
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Page 54: ...Section 1 Overview Rev 1 00 Apr 28 2008 Page 28 of 994 REJ09B0452 0100...
Page 92: ...Section 2 CPU Rev 1 00 Apr 28 2008 Page 66 of 994 REJ09B0452 0100...
Page 158: ...Section 5 Interrupt Controller Rev 1 00 Apr 28 2008 Page 132 of 994 REJ09B0452 0100...
Page 244: ...Section 8 8 Bit PWM Timer PWMU Rev 1 00 Apr 28 2008 Page 218 of 994 REJ09B0452 0100...
Page 330: ...Section 10 16 Bit Timer Pulse Unit TPU Rev 1 00 Apr 28 2008 Page 304 of 994 REJ09B0452 0100...
Page 416: ...Section 13 8 Bit Timer TMR Rev 1 00 Apr 28 2008 Page 390 of 994 REJ09B0452 0100...
Page 612: ...Section 18 I 2 C Bus Interface IIC Rev 1 00 Apr 28 2008 Page 586 of 994 REJ09B0452 0100...
Page 706: ...Section 20 LPC Interface LPC Rev 1 00 Apr 28 2008 Page 680 of 994 REJ09B0452 0100...
Page 752: ...Section 21 FSI Interface Rev 1 00 Apr 28 2008 Page 726 of 994 REJ09B0452 0100...
Page 774: ...Section 23 RAM Rev 1 00 Apr 28 2008 Page 748 of 994 REJ09B0452 0100...
Page 1008: ...Section 28 Electrical Characteristics Rev 1 00 Apr 28 2008 Page 982 of 994 REJ09B0452 0100...
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