Rainbow Electronics AT89C51SND1C - Manual (Page 30)

30
AT8xC51SND1C
4109E–8051–06/03
Special Function
Registers
The Special Function Registers (SFRs) of the AT8xC51SND1C derivatives fall into the
categories detailed in Table 30 to Table 46. The relative addresses of these SFRs are
provided together with their reset values in Table 47. In this table, the bit-addressable
registers are identified by Note 1.
Note: 1. ENBOOT bit is only available in AT89C51SND1C product.
Table 30. C51 Core SFRs
Mnemonic Add Name 7 6 5 4 3 2 1 0
ACC E0h Accumulator
B F0h B Register
PSW D0h Program Status Word CY AC F0 RS1 RS0 OV F1 P
SP 81h Stack Pointer
DPL 82h Data Pointer Low Byte
DPH 83h Data Pointer High Byte
Table 31. System Management SFRs
Mnemonic Add Name 7 6 5 4 3 2 1 0
PCON 87h Power Control SMOD1 SMOD0 - - GF1 GF0 PD IDL
AUXR 8Eh Auxiliary Register 0 - EXT16 M0 DPHDIS XRS1 XRS0 EXTRAM AO
AUXR1 A2h Auxiliary Register 1 - - ENBOOT (1) - GF3 0 - DPS
NVERS FBh Version Number NV7 NV6 NV5 NV4 NV3 NV2 NV1 NV0
Table 32. PLL and System Clock SFRs
Mnemonic Add Name 7 6 5 4 3 2 1 0
CKCON 8Fh Clock Control - - - - - - - X2
PLLCON E9h PLL Control R1 R0 - - PLLRES - PLLEN PLOCK
PLLNDIV EEh PLL N Divider - N6 N5 N4 N3 N2 N1 N0
PLLRDIV EFh PLL R Divider R9 R8 R7 R6 R5 R4 R3 R2
Table 33. Interrupt SFRs
Mnemonic Add Name 7 6 5 4 3 2 1 0
IEN0 A8h Interrupt Enable Control 0 EA EAUD EMP3 ES ET1 EX1 ET0 EX0
IEN1 B1h Interrupt Enable Control 1 - EUSB - EKB EADC ESPI EI2C EMMC
IPH0 B7h Interrupt Priority Control High 0 - IPHAUD IPHMP3 IPHS IPHT1 IPHX1 IPHT0 IPHX0
IPL0 B8h Interrupt Priority Control Low 0 - IPLAUD IPLMP3 IPLS IPLT1 IPLX1 IPLT0 IPLX0
IPH1 B3h Interrupt Priority Control High 1 - IPHUSB - IPHKB IPHADC IPHSPI IPHI2C IPHMMC
IPL1 B2h Interrupt Priority Control Low 1 - IPLUSB - IPLKB IPLADC IPLSPI IPLI2C IPLMMC