The Texas Instruments datasheet for the MSP430G2553 (Literature Number SLAS735J
ID: 2267961 • Letter: T
Question
The Texas Instruments datasheet for the MSP430G2553 (Literature Number SLAS735J Revised May 2013, Table 8) indicates the following use of “low memory” addresses: • 8-bit SFRs (special function registers) are memory mapped between addresses “0Fh to 00h”
• 8-bit peripheral registers are memory mapped between addresses “0FFh to 010h”
• 16-bit peripheral registers are memory mapped between addresses “01FFh to 0100h”
There are several aspects of this information that seem confusing (at least to Jerry).
(a) Rephrase or reword the three address range descriptions, e.g. “0Fh to 00h,” by correcting the relative order of the values given, the number of digits used in the representations, and apply prefix notation, (0x), to specify the base of the number system used.
(b) Compute the total number of bytes in each of the three identified address spaces.
Explanation / Answer
a. Since MSP430 series of micro-controllers has 16 bit ALU all the data is 16 bit long and is represented by four hexadecimal values. Thus for eaxmple 0Fh corresponds to a value of 0x000F where prefix 0x represents that hexadecimal format is used. In similar fasion we can construct the table below
b)
i) For the 8 bit ( 1byte long SFRs) we have (0x000F-0x0000+1) memory sapces which corresponds to 16 registers each 1 byte long which totals to 16 bytes.
ii) For the 8 bit peripheral registers ( 1 byte long) we have (0x00FF-0x0010+1) memory spaces that corresponds to 240 addresses that totals up to 1920 bytes.
iii) For the 16 bit peripheral registers (2 bytes long) we have (0x01FF-0x0100+1) memory spaces that corresponds to 256 spaces that addd up to 512 bytes of space.
Peripherals Given Range Rephrased Range 8 bit SFRs 0Fh to 00h 0x0000 to 0x000F 8 bit peripheral registers 0FFh to 010h 0x0010 to 0x00FF 16 bit peripheral registers 01FFh to 0100h 0x0100 to 0x01FFRelated Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.