ZLF645 MAXIM [Maxim Integrated Products], ZLF645 Datasheet - Page 63

• Manufacturer Part Number: ZLF645
• Description: Flash MCUs with Learning Amplification
• Manufacturer: MAXIM [Maxim Integrated Products]

19-4572; Rev 0; 4/09
START
Caution:
Figure 17. Interfacing the In-Circuit Programming Pin P34 with an RS-232 Interface (2)
ICP Data Format
ICP Auto-Baud Detector/Generator
The ICP interface uses the asynchronous data format defined for RS-232. Each character
is transmitted as 1 Start bit, 8 data bits (least significant bit first), and 1.5 Stop bits
(see
To run over a range of baud rates (data bits per second) with various system clock
frequencies, the ICP contains an Auto-Baud Detector/Generator. After a reset, the ICP is
non-active until it receives data. The ICP requires that the first character sent from the host
is character
data bits), framed between High bits. The Auto-Baud Detector measures this period and
sets the ICP Baud Rate Generator accordingly.
The Auto-Baud Detector/Generator is clocked by the system clock. The minimum baud
rate is the system clock frequency divided by 512. If the datastream can be synchronized
with the system clock, the auto-baud generator can run as high as the system clock
frequency divided by 2.
D0
RS-232 TX
RS-232 RX
For operation of the ICP, all power pins (V
and all ground pins (V
Figure
D1
18).
80H
. The character
D2
Figure 18. ICP Data Format
Transceiver
SS
RS-232
and AV
D3
80H
SS
) must be properly grounded.
has eight continuous bits Low (one Start bit plus 7
Open-Drain
D4
Buffer
DD
and AV
V DD
D5
10 K
DD
ZLF645 Series Flash MCUs
) must be supplied with power
D6
ICP Pin
Product Specification
ICP Interface Operation
D7
STOP
55