LSPC2-A2
The LSPC chips are only found in cartridge systems, they provide pixel data for the Video DAC. (the line buffer for color data is most likely in the NEO-B1 but don't know for sure...).
LSPC-A0 chips can be found on early MVS slots and AES systems and work alongside the PRO-B0 chip. LSPC2-A2 chips are found in second revision systems and work with the NEO-B1 chip.
Graphics
Two separate buses run in parallel to fetch data from VRAM for rendering the screen. Each bus connects to a pair of 8bit chips, forming a 16bit bus.
- VRAM 0000-7FFF - 2x 62256/43256 (120ns(?) or faster)
- VRAM 8000-87FF - 2x 5814/5863/6116 (45ns or faster)
The LSPC arbitrates all VRAM access and allows for 68k access at any time during rendering without display glitches. The interface is slow and data writes are ignored when games write VRAM too quickly, especially with overclocked systems *specifics go here maybe*.
It shares a 24bit bus with the NEO-B1 which goes out to the CHA connector on the cart slot for addressing S ROMs, C ROMs and the on-board LO ROM.
IRQ
All 3 68k interrupts are generated by this chip.
Pinout
LSPC2-A2
D0~D3:2~5 GND:6 D4~D6:7~9 D7:10 11 VCC:12 D8~D11:13~16 GND:17 D12~D15:18~21 GND:22 B0~B4:23~27 28 B5~B8:29~32 VCC:33 B9~B13:34~38 GND:39 B14:40 E0~E8:41~49 GND:50 E9~E13:51~55 VCC:56? E14~E15:57~58 BOE:59? BWE:60? GND:61 REF:62? 63 INT:64 DOTA:65 DOTB:66 F0~F4:67~71 GND:72 F5~F8:73~76 VCC:77 F9,F10:78,79 F11~F13:80~82 GND:83 F14,F15:84,85 86 87 88 89 90 C3~C5:91~93 GND:94 C6~C10:95~99 VCC:100 4H:101 CC4:102 PK1:103 PK2:104 GND:105 1H1:106 2H1:107 SCH?:108 H:109 EVEN1:110 EVEN2:111 P0~P3:112~115 GND:116 P4~P7:117~120 VCC:121 P8~P13:122~126 GND:127 128 P14~P15:129,130 DIVO:131 TST0:132 133 P16~P19:134~137 GND:138 139 140 141 142 DIVI:143 VCC:144 VCS:145 RESETF:146 LOAD:147 148 GND?:149 SYNC:150 ?NK2:151 CM?L:152 SL1?:153 SL2?:154 WE1~WE4:155~158 CK1:159 GND:160 CK2~CK4:161~163 SS1,SS2:164~165 VCC:166 IP0:167 IP1:168 RES:169 24H?:170 GND:171 LSPOE:172 LSPWE:173 A1~A3:174~176
CWE:?? SW?:14? TST:??