s5u1c33000c Epson Electronics America, Inc., s5u1c33000c Datasheet - Page 100

• Manufacturer Part Number: s5u1c33000c
• Description: Cmos 32-bit Single Chip Microcomputer S5u1c33000c Manual
• Manufacturer: Epson Electronics America, Inc.

CHAPTER 6: C COMPILER
6.5.2 Data Representation
The gcc33 supports all data types under ANSI C. Table 6.5.2.1 below lists the size of each type (in bytes) and the
effective range of numeric values that can be expressed in each type.
The float and double types conform to IEEE standard formats.
Store positions in memory
Structure data
84
The positions in the memory where data is stored depend on the type. Regardless of whether it is global or
local, data is located in the memory in as many bytes as are determined by the size beginning with an
address that can be divided by the size.
The double type is aligned at 4-byte boundary addresses, so that the 4 low-order bytes of data (mantissa part
(31–0)) are stored in 4 bytes of low-order locations of memory, and the 4 high-order bytes of data (sign,
exponent, and mantissa part (51–32)) are stored in 4 bytes of high-order memory locations.
Structure data is located in the memory beginning with 4-byte boundaries (addresses divided by 4) in the
same way as stated above for the double type. Members are located in the memory according to the size of
each data type in the order they are defined.
The following shows an example of how structure is defined, and where it is located.
Example: struct Sample {
As shown in the diagram above, some unused areas may remain in the memory depending on the data type
of a member.
Low memory
};
char
unsigned char
short
unsigned short
int
unsigned int
long
unsigned long
pointer
float
double
char
short
char
int
double
Data type
Start address
Fig. 6.5.2.1 Sample locations of structure data in the memory
cData;
hData;
cArray[3];
iData;
dData;
Size
1
1
2
2
4
4
4
4
4
4
8
Table 6.5.2.1 Data type and size
+16
+12
-128 to 127
0 to 255
-32768 to 32767
0 to 65535
-2147483648 to 2147483647
0 to 4294967295
-2147483648 to 2147483647
0 to 4294967295
0 to 4294967295
1.175e-38 to 3.403e+38 (normalized number)
2.225e-308 to 1.798e+308 (normalized number)
+8
+4
+0
cData
EPSON
Effective range of a number
+0
(C COMPILER PACKAGE FOR S1C33 FAMILY) (Ver. 4)
cArray[3]
Unused
+1
dData (high)
dData (low)
iData
+2
hData
S5U1C33000C MANUAL
Unused
+3