MC80F0204 Datasheet, PDF (113/126 Pages) List of Unclassifed Manufacturers – 8-BIT SINGLE-CHIP MICROCONTROLLERS

Preliminary
MC80F0104/0204
26.3 Hardware Conditions to Enter the ISP Mode
The In-System Programming (ISP) is performed without
removing the microcontroller from the system. The In-
System Programming (ISP) facility consists of a series of
internal hardware resources coupled with internal firm-
ware through the serial port. The In-System Programming
(ISP) facility has made in-circuit programming in an em-
bedded application possible with a minimum of additional
expense in components and circuit board area. The boot
loader can be executed by holding ALE high, RESET /V_PP
as +9V, and ACLK with the OSC. 1.8432MHz. The ISP
function uses five pins: TxD, RxD, ALE, ACLK and RE-
SET/V_PP.
V_DD(+5V)
MCU_RxD
MCU_TxD
ACLK_CLK
High(1)
R04 / RxD
1
R05 / TxD
2
R05 / ACLK
3
4
V_DD
5
ALE R10
6
7
8
9
10
20
19
18
17
16
V_SS
15
RESET RESET / VPP
+9V
14
X_OUT
13
X_IN
X-TAL
2MHz~12MHz
12
11
ISP Configuration
Note: Considerations to implement ISP function in a user
target board
• The ACLK must be connected to the specifed
oscillator.
• Connect the +9V to RESET/Vpp pin directly.
• The ALE pin must be pulled high.
• The main clk must be higher than 2MHz.
Mar. 2005 Ver 0.2
109