Maxim Integrated 73S12xxF Software - Manual (Page 20)

73S12xxF Software User Guide UG_12xxF_016
20 Rev. 1.50
4.1.2 External Data Memory
The 2 KB of XRAM are available at address locations 0x0000 through 0x07FF. The upper 1K bytes of
the external data memory space (from 0xFC00 to 0xFFFF) is reserved for additional special function
registers for the 73S12xxF chip and is segmented as shown in
Table 1.
Table 1: Upper 1 KB External Data Memory layout
Function Space # Bytes Starting Address Ending Address
Peripheral Control 128 0xFF80 0xFFFF
Smart Card Control 384 0xFE00 0xFF7F
USB Control 512 0xFC00 0xFDFF
4.1.3 Internal Data Memory
The 256 bytes of IRAM are available for use as scratch-pad RAM.
The IRAM Special Function Registers are mapped as shown in
Table 2 . All registers appearing in the
first column (000b) are bit-addressable:
Table 2: IRAM Special Function Register Map
HEX/BIN 000b 001b 010b 011b 100b 101b 110b 111b
0xF8 - 0xFF
0xF0 - 0xF7 b
0xE8 - 0xEF
0xE0 - 0xE7 acc
0xD8 - 0xDF wdcon
0xD0 - 0xD7 psw kcol krow kscan kstat ksize korderl korderh
0xC8 - 0xCF t2con
0xC0 - 0xC7 ircon
0xB8 - 0xBF ien1 ip1 s0relh s1relh
0xB0 - 0xB7 p3 flshctl pgadr
0xA8 - 0xAF ien0 ip0 s0rell
0xA0 - 0xA7 usr15
8
udir15
8
0x98 - 0x9F s0con sobuf ien2 s1con s1buf s1rell
0x90 - 0x97 usr70 udir70 dps erase
0x88 - 0x8F tcon tmod tl0 tl1 th0 th1 ckcon mclkctl
0x80 - 0x87 sp dp1 dph dpl1 dph1 wdtrel pcon
4.2 Low-level API
A low-level Application Programming Interface (API) is provided to control all hardware peripherals. An
application can link to the low-level API library to utilize the functions described in subsequent sections.
Before using the low-level API, an embedded application should call the API_Init() routine in the
beginning of the program as part of its initialization. As a general guideline, any feature to be included or
used in an application must first call its associated initialization routine. For example, to link the USB
module into an application, USB_Init() must first be called to initialize its associated registers for the USB
functions.
Each feature available with the 73S12xxF device has a sample application to demonstrate the library
function’s usage.