SM59A16U1
8-Bit Micro-controller
64KB with ISP Flash
& 6K+256B RAM embedded
21. In-System Programming ( Internal ISP )
The SM59A16U1 can generate flash control signal by internal hardware circuit. Users utilize flash control register, flash
address register and flash data register to perform the ISP function without removing the SM59A16U1 from the system.
The SM59A16U1 provides internal flash control signals which can do flash program/chip erase/page erase/protect
functions. User need to design and use any kind of interface which SM59A16U1 can input data. User then utilize ISP
service program to perform the flash program/chip erase/page erase/protect functions.
21.1
ISP service program
The ISP service program is a user developed firmware program which resides in the ISP service program space. After
user developed the ISP service program, user then determine the size of the ISP service program. User need to
program the ISP service program in the SM59A16U1 for the ISP purpose.
The ISP service programs were developed by user so that it should includes any features which relates to the flash
memory programming function as well as communication protocol between SM59A16U1 and host device which output
data to the SM59A16U1. For example, if user utilize UART interface to receive/transmit data between SM59A16U1 and
host device, the ISP service program should include baud rate, checksum or parity check or any error-checking
mechaniOB to avoid data transmission error.
The ISP service program can be initiated under SM59A16U1 active or idle mode. It can not be initiated under power
down mode.
21.2
Lock Bit ( N )
The Lock Bit N has two functions: one is for service program size configuration and the other is to lock the ISP service
program space from flash erase function.
The ISP service program spaces address range 0xF000h to 0xFFFFh. It can be divided as blocks of N*256 byte. (N=0
to 16). When N=0 means no ISP function, all of 64K byte flash memory can be used as program memory. When N=1
means ISP service program occupies 256 byte while the rest of 63.75K byte flash memory can be used as program
memory. The maximum ISP service program allowed is 4K byte when N=16. Under such configuration, the usable
program memory space is 60K byte.
After N determined, SM59A16U1 will reserve the ISP service program space downward from the top of the program
address 0xFFFFh. The start address of the ISP service program located at 0xFx00h, x is depends on the lock bit N. As
given in Table 21-1.
The lock bit N function is different from the flash protect function. The flash erase function can erase all of the flash
memory except for the locked ISP service program space. If the flash not has been protected, the content of ISP
service program still can be read. If the flash has been protected, the overall content of flash program memory space
including ISP service program space cannot be read.
Specifications subject to change without notice contact your sales representatives for the most recent information.
ISSFD-M071
Ver A SM59A16U1 04/12/2013
- 134 -
SYNCMOS [ SYNCMOS TECHNOLOGIES,INC ]
