Spare Time Gizmos
SBC6120 User's Manual
03/09/2003 1:35 PM
Page 51
D. IOT R
EFERENCE
IOT
O
PCODE
G1
21
G2
C0
22
C1
SKIP
BYTE
23
D
ESCRIPTION
C
ONSOLE
T
ERMINAL
24
KSF
6031
•
•
25
Skip if console receive flag is set (section 3.3)
KCC
6032
•
•
Clear console receive flag and AC
KRS
6034
•
•
•
OR AC with console receive buffer
KRB
6036
•
•
•
•
Read receive buffer into AC and clear the flag
TSF
6041
•
•
26
Skip if console transmit flag is set
TCF
6042
•
Clear transmit flag, but not the AC
TPC
6044
•
Load AC into transmit buffer, but don't clear flag
TLS
6046
•
Load AC into transmit buffer and clear the flag
IDE I
NTERFACE
(8255 PPI)
PRPA
6470
•
•
•
Read PPI port A (section 3.5)
PRPB
6471
•
•
•
Read PPI port B
PRPC
6472
•
•
•
Read PPI port C
PWPA
6474
•
Write PPI port A and clear the AC
PWPB
6475
•
Write PPI port B and clear the AC
PWPC
6476
•
Write PPI port C and clear the AC
PWCR
6477
•
Write PPI Control Register and clear the AC
21
G1 and G2 refer to the
IOT GROUP 1 L
and
IOT GROUP 2 L
signals exchanged between the IOT1 GAL and the IOT2 GAL.
22
This table shows the logical state of the
C0 L
,
C1 L
,
SKIP L
and
BYTE READ L
signals, however remember that these are active low. Thus a
signal which is TRUE (asserted) in this table will be low.
23
This refers to the signal
BYTE READ L
, which forces the four most significant DX bits to zero during an I/O read from an 8 bit device.
24
The KL8E IOTs 6030 (
KCC
), 6035 (
KIE
), 6040 (
SPF
), and 6045 (
SPI
) are not implemented by the SBC6120. The IOTs 6033, 6037, 6043, and
6047 are not implemented by either the SBC6120 or the KL8E. All these IOTs function as no-ops.
25
KEYBOARD FLAG H
26
PRINTER FLAG H