Data Link Format; Serial Byte Format - Intel iUP-200A User Manual

Host Serial Command Protocol
D ata L ink Format
All records passed between the host and the universal programmer are sent a byte
at a time. Each byte received by the universal programmer must be prefixed by a
start bit and suffixed with at least one stop bit. All bytes transmitted by the univer­
sal programmer are prefixed with one start bit and suffixed with one stop bit.
Figure B-3 shows the typical format for passing bytes over the serial data link.
On power-up or reset or when the serial data link baud rate is changed, the host
system must transmit a Clear (C) command. The C command is used by the uni­
versal programmer processor to automatically set the baud rate. If the baud rate is
changed after it is initially identified, three sequential check-sum errors occur
before the new rate is identified. This means that four clear commands must be
sent before the new rate is identified.
START
DO
BIT
i
— I — l
i
i
i
i
i
l D1 D2 D3
I
l
i
i i
__1 __ __1 __
Figure B-3 Serial Byte Format
— i—
1 l — 1 —
i
i i
i
i I i
I
D4 D5 D6
I i I
i
i l
__1 __
iUP-200A/201A
STOP
D7
BIT(S)
0156