3 MeMORY MaP
3-6
Seiko epson Corporation
S1C17624/604/622/602/621 TeChniCal Manual
D[2:0]
FlCYC[2:0]: FlaShC Read access Cycle Bits
Sets the number of read access cycles for the Flash controller.
2.4.1 Setting Read Access Cycles for the Flash Controller
Table 3.
FlCYC[2:0]
number of read access cycles
CClK frequency
0x7–0x5
Reserved
–
0x4
1 cycle
8.2 MHz max.
0x3
5 cycles
0x2
4 cycles
0x1
3 cycles
0x0
2 cycles
(Default: 0x3)
notes: • Be sure to avoid setting a number of read access cycles that exceeds the maximum allowable
CCLK frequency, as it may cause a malfunction.
• For maximum performance, set FLCYC[2:0] to 0x4.
internal RaM area
3.3
embedded RaM
3.3.1
The S1C17624/604 contains an 8K-byte RAM, the S1C17622/602 contains a 4K-byte RAM, and the S1C17621
contains a 2K-byte RAM.
3.1.1 Embedded RAM
Table 3.
S1C17624/604
S1C17622/602
S1C17621
RAM capacity
8K bytes
4K bytes
2K bytes
Address range
0x0 to 0x1fff
0x0 to 0xfff
0x0 to 0x7ff
The RAM is accessed in one cycle for reading/writing and allows high-speed execution of the instruction codes
copied into it as well as storing variables and other data.
note: The 64-byte area at the end of the RAM (S1C17624/604: 0x1fc0–0x1fff, S1C17602: 0xfc0–0xfff)
is reserved for the on-chip debugger. When using the debug functions under application develop-
ment, do not access this area from the application program. This area can be used for applica-
tions of mass-produced devices that do not need debugging.
The S1C17624/604 enables the RAM size used to apply restrictions to 8KB, 4KB, or 2KB. The S1C17622 enables
the RAM size used to apply restrictions to 4KB or 2KB. For example, when using the S1C17624/604/622 to devel-
op an application for a built-in ROM model, you can set the RAM size to match that of the target model, preventing
creating programs that seek to access areas outside the RAM areas of the target product. The RAM size is selected
using IRAMSZ[2:0]/MISC_IRAMSZ register.
iRaM Size Select Register (MiSC_iRaMSZ)
Register name address
Bit
name
Function
Setting
init. R/W
Remarks
iRaM Size
Select Register
(MiSC_iRaMSZ)
(S1C17624/604)
0x5326
(16 bits)
D15–9 –
reserved
–
–
–
0 when being read.
D8
DBaDR
Debug base address select
1 0x0
0 0xfffc00
0
R/W
D7
–
reserved
–
–
–
0 when being read.
D6–4 –
reserved
–
–
–
0x1 when being read.
D3
–
reserved
–
–
–
0 when being read.
D2–0 iRaMSZ[2:0] IRAM size select
IRAMSZ[2:0]
Size
0x1 R/W
0x3
0x2
0x1
Other
2KB
4KB
8KB
reserved